fix(stats): stop counting duplicate typeset subtitle lines (#191)

.agents/plugins/marketplace.json

@@ -1,20 +0,0 @@
-{
-  "name": "subminer-local",
-  "interface": {
-    "displayName": "SubMiner Local"
-  },
-  "plugins": [
-    {
-      "name": "subminer-workflow",
-      "source": {
-        "source": "local",
-        "path": "./plugins/subminer-workflow"
-      },
-      "policy": {
-        "installation": "AVAILABLE",
-        "authentication": "ON_INSTALL"
-      },
-      "category": "Productivity"
-    }
-  ]
-}

.agents/skills/subminer-change-verification/SKILL.md

@@ -1,22 +1,45 @@
 ---
-name: 'subminer-change-verification'
-description: 'Compatibility shim. Canonical SubMiner change verification workflow now lives in the repo-local subminer-workflow plugin.'
+name: subminer-change-verification
+description: Verify SubMiner changes with repo-native cheap-first test lanes. Use after code, config, launcher, plugin, runtime, stats, documentation, or workflow changes; do not use for read-only questions.
 ---
 
-# Compatibility Shim
+# SubMiner Change Verification
 
-Canonical source:
+Verify the behavior claimed by a change without running unrelated expensive checks by default.
 
-- `plugins/subminer-workflow/skills/subminer-change-verification/SKILL.md`
+## Workflow
 
-Canonical helper scripts:
+1. Inspect the requested scope and changed paths with `git status --short` and `git diff`.
+2. Read `docs/workflow/verification.md` as the source of truth for maintained lanes.
+3. Run the cheapest lane or lanes that cover the changed behavior.
+4. Escalate to the full handoff gate only for substantial or cross-boundary changes.
+5. Report exact commands, results, skipped checks, blockers, and remaining risk.
 
-- `plugins/subminer-workflow/skills/subminer-change-verification/scripts/classify_subminer_diff.sh`
-- `plugins/subminer-workflow/skills/subminer-change-verification/scripts/verify_subminer_change.sh`
+Do not use hidden wrapper commands. Verification commands are owned by `package.json` and the workflow documentation.
 
-When this shim is invoked:
+## Lane Selection
 
-1. Read the canonical plugin-owned skill.
-2. Follow the plugin-owned skill as the source of truth.
-3. Use the wrapper scripts in this shim directory only for compatibility with existing commands and docs.
-4. Do not duplicate workflow changes here; update the plugin-owned skill and scripts instead.
+- Internal docs, `AGENTS.md`, or `.agents/skills/**`: `bun run test:docs:kb`
+- User-facing `docs-site/**`: `bun run docs:test`, then `bun run docs:build`
+- Config/schema/defaults: `bun run test:config`
+  - If defaults or templates changed, also run `bun run generate:config-example` and `bun run verify:config-example`.
+- General TypeScript source: `bun run typecheck`, then `bun run test:fast`
+- Launcher or mpv plugin: `bun run test:launcher` or `bun run test:env`, based on the behavior changed
+- Runtime compatibility or dist-sensitive wiring: `bun run test:runtime:compat`
+- Stats dashboard: `bun run test:stats`
+- Build/release scripts: `bun run test:scripts`
+
+For substantial changes, use the full gate documented in `AGENTS.md` and `docs/workflow/verification.md`.
+
+## Runtime Escalation
+
+Real runtime checks are required when the claim depends on actual Electron, mpv, overlay, focus, window tracking, launch, or socket behavior. Run the relevant application flow when the environment supports it. Otherwise, report the missing runtime dependency and do not present cheaper checks as authoritative runtime validation.
+
+## Pre-Handoff Checks
+
+Before handoff, reconcile both questions:
+
+1. Do behavior, defaults, flags, shortcuts, ports, APIs, architecture, or workflow changes require documentation updates?
+2. Does the change require a current-outcome fragment under `changes/` according to `changes/README.md`?
+
+Complete required updates before handoff or report the blocker.

.agents/skills/subminer-change-verification/scripts/classify_subminer_diff.sh

@@ -1,13 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
-REPO_ROOT=$(cd "$SCRIPT_DIR/../../../.." && pwd)
-TARGET="$REPO_ROOT/plugins/subminer-workflow/skills/subminer-change-verification/scripts/classify_subminer_diff.sh"
-
-if [[ ! -x "$TARGET" ]]; then
-  echo "Missing canonical script: $TARGET" >&2
-  exit 1
-fi
-
-exec "$TARGET" "$@"

.agents/skills/subminer-change-verification/scripts/verify_subminer_change.sh

@@ -1,13 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
-REPO_ROOT=$(cd "$SCRIPT_DIR/../../../.." && pwd)
-TARGET="$REPO_ROOT/plugins/subminer-workflow/skills/subminer-change-verification/scripts/verify_subminer_change.sh"
-
-if [[ ! -x "$TARGET" ]]; then
-  echo "Missing canonical script: $TARGET" >&2
-  exit 1
-fi
-
-exec "$TARGET" "$@"

.agents/skills/subminer-scrum-master/SKILL.md

@@ -1,18 +0,0 @@
----
-name: 'subminer-scrum-master'
-description: 'Compatibility shim. Canonical SubMiner scrum-master workflow now lives in the repo-local subminer-workflow plugin.'
----
-
-# Compatibility Shim
-
-Canonical source:
-
-- `plugins/subminer-workflow/skills/subminer-scrum-master/SKILL.md`
-
-When this shim is invoked:
-
-1. Read the canonical plugin-owned skill.
-2. Follow the plugin-owned skill as the source of truth.
-3. Do not duplicate workflow changes here; update the plugin-owned skill instead.
-
-This shim exists so existing repo references and prompts keep resolving during the migration to the repo-local plugin workflow.

AGENTS.md

@@ -1,4 +1,4 @@
-# AGENTS.MD
+# AGENTS.md
 
 ## Internal Docs
 
@@ -13,7 +13,7 @@ Start here, then leave this file.
 
 `docs-site/` is user-facing. Do not treat it as the canonical internal source of truth.
 
-`CLAUDE.md` is a symlink to this file — there is one project instruction file, not two.
+`CLAUDE.md` is a symlink to this file; there is one project instruction file, not two.
 
 ## Quick Start
 
@@ -25,8 +25,9 @@ Start here, then leave this file.
 
 ## Build / Test
 
-- Runtime/package manager: Bun (`packageManager: bun@1.3.5`)
-- Default handoff gate:
+- Runtime/package manager: Bun; use the version pinned by `package.json`.
+- Follow [`docs/workflow/verification.md`](./docs/workflow/verification.md) and start with the cheapest sufficient lane.
+- Full handoff gate for substantial changes:
   `bun run typecheck`
   `bun run test:fast`
   `bun run test:env`
@@ -44,13 +45,15 @@ Start here, then leave this file.
 - Runtime-compat / dist-sensitive: `bun run test:runtime:compat`
 - Stats dashboard UI (`stats/`): `bun run test:stats`
 - Build/release scripts (`scripts/**`): `bun run test:scripts`
-- Docs-only: `bun run docs:test`, then `bun run docs:build`
+- Internal docs, `AGENTS.md`, or repo skills: `bun run test:docs:kb`
+- User-facing `docs-site/`: `bun run docs:test`, then `bun run docs:build`
+- macOS mpv window helper: `bun test scripts/get-mpv-window-macos.test.ts`
 - Test lanes are directory-discovered via `scripts/test-lanes.ts`; never hand-list test files in `package.json`
 
 ## Docs Upkeep
 
 - Docs ship with the change, not after. If a change alters behavior, defaults, flags, shortcuts, ports, or APIs, update the matching docs in the same PR. Touching code without reconciling its docs is an incomplete change.
-- Source of truth for config defaults is the generated `config.example.jsonc`. Never write a default value into prose you didn't read from it — and don't restate the same default across multiple docs; cite/link to one place so there's a single thing to update.
+- Source of truth for config defaults is the generated `config.example.jsonc`. Never write a default value into prose you didn't read from it, and don't restate the same default across multiple docs; cite/link to one place so there's a single thing to update.
 - Trigger map (touch left → update right):
   - `src/config/definitions/**` (schema/defaults/template) → `bun run generate:config-example`, then reconcile `docs-site/configuration.md` + any feature doc that cites that default
   - shortcuts/keybindings (`shortcuts.*`, `keybindings`, `stats.*Key`, `subtitleSidebar.toggleKey`, controller bindings) → `docs-site/shortcuts.md`
@@ -71,16 +74,10 @@ Start here, then leave this file.
 
 ## Release / PR Notes
 
-- User-visible PRs need reconciled current-outcome fragment(s) in `changes/*.md` — format and rules in [`changes/README.md`](./changes/README.md) (`type` + `area` keys required; inspect existing same-PR fragments, then update/remove stale bullets or add only genuinely separate outcomes; apply the `skip-changelog` label to opt out)
+- User-visible PRs need reconciled current-outcome fragment(s) in `changes/*.md`. Format and rules live in [`changes/README.md`](./changes/README.md) (`type` + `area` keys required; inspect existing same-PR fragments, then update/remove stale bullets or add only genuinely separate outcomes; apply the `skip-changelog` label to opt out).
 - User-visible docs changes get a `type: docs` fragment
 - CI enforces `bun run changelog:lint` and `bun run changelog:pr-check`
 - PR review helpers:
-  - `gh pr view --json number,title,url --jq '"PR #\\(.number): \\(.title)\\n\\(.url)"'`
+  - `gh pr view --json number,title --jq '"PR #\\(.number): \\(.title)"'`
   - `gh api repos/:owner/:repo/pulls/<num>/comments --paginate`
-
-## Runtime Notes
-
-- Use Codex background for long jobs; tmux only when persistence/interaction is required
-- CI red: `gh run list/view`, rerun, fix, repeat until green
-- TypeScript: keep files small; follow existing patterns
-- Only Swift is the `scripts/get-mpv-window-macos.swift` helper (macOS mpv window detection); validate via `bun test scripts/get-mpv-window-macos.test.ts`
+- For CI debugging, inspect runs with `gh run list/view`; rerun or fix only within the requested scope.

changes/audio-generation-network-mounts.md

@@ -0,0 +1,4 @@
+type: fixed
+area: Anki media
+
+- Fixed sentence-audio generation timing out on slow network-mounted MKV files with many subtitle and font-attachment streams. Selected audio tracks now use bounded FFmpeg probing and a two-minute extraction budget, and missing output reports a clear FFmpeg error instead of raw `ENOENT`.

changes/duplicate-line-stats-cleanup.md

@@ -0,0 +1,5 @@
+type: fixed
+area: stats
+
+- Typeset subtitles no longer flood the stats. Karaoke openings and animated signs are authored as one subtitle event per animation frame, and immersion tracking counted every frame, which was enough to put an OP lyric at the top of "Top Repeated Words" for good. Lines are now collapsed on the way in using the same rules the subtitle sidebar already applies: matching parsed timings record exactly the cues the sidebar shows, while shifted, changing, or unparsed sources use a strict fallback where identical, contiguous, sub-0.1s lines stop counting after a few frames. Ordinary repeated dialogue and rewatches are unaffected.
+- Added a cleanup for stats already affected. The Vocabulary tab has a **Duplicates** button that scans a chosen window (7 days through all time), shows the bursts it found and the word and kanji counts they added, and collapses each run to one line once confirmed. `subminer stats cleanup --duplicate-lines` does the same from the terminal, with `--dry-run` and `--lookback-days <n>`. Only subtitle lines and the vocabulary counts they feed are touched; watch time and lines-seen totals are left as recorded.

docs-site/immersion-tracking.md

@@ -34,7 +34,7 @@ The same immersion data powers the stats dashboard.
 - In-app overlay: focus the visible overlay, then press the key from `stats.toggleKey` (default: `` ` `` / `Backquote`).
 - Launcher command: run `subminer stats` to start the local stats server on demand (it also opens the dashboard in your browser when `stats.autoOpenBrowser` is enabled; the default is `false`).
 - Background server: run `subminer stats -b` to start or reuse a dedicated background stats daemon without keeping the launcher attached, and `subminer stats -s` to stop that daemon.
-- Maintenance commands: run `subminer stats cleanup` or `subminer stats cleanup -v` to backfill/repair vocabulary metadata (`headword`, `reading`, POS) and purge stale or excluded rows from `imm_words` on demand; `subminer stats cleanup -l` repairs lifetime summary tables. `subminer stats rebuild` and `subminer stats backfill` rebuild or backfill rollup data.
+- Maintenance commands: run `subminer stats cleanup` or `subminer stats cleanup -v` to backfill/repair vocabulary metadata (`headword`, `reading`, POS) and purge stale or excluded rows from `imm_words` on demand; `subminer stats cleanup -l` repairs lifetime summary tables; `subminer stats cleanup --duplicate-lines` collapses repeated lines left behind by typeset subtitles (see [Repeated Line Cleanup](#repeated-line-cleanup)). `subminer stats rebuild` and `subminer stats backfill` rebuild or backfill rollup data.
 - Browser page: open `http://127.0.0.1:6969` directly if the local stats server is already running.
 
 ### Dashboard Tabs
@@ -125,6 +125,34 @@ Secondary subtitle text (typically English translations) is stored alongside pri
 
 The Vocabulary tab toolbar includes an **Exclusions** button for hiding words from all vocabulary views. Excluded words are stored in the immersion database, with older browser localStorage exclusions imported on first load after upgrade. They can be managed (restored or cleared) from the exclusion modal. Exclusions affect stat cards, charts, the frequency rank table, and the word list.
 
+### Repeated Line Cleanup
+
+Karaoke openings and animated signs are authored as one subtitle event per animation frame, all carrying the same text. Playback reports every one of those frames, so a single OP lyric could be recorded hundreds of times and dominate "Top Repeated Words".
+
+Recording now collapses those runs as they happen, matching what the subtitle sidebar shows:
+
+- When the active subtitle source has been parsed, its cue list has already had duplicate events and animation bursts merged. A line landing inside a surviving cue but after that cue's start is a frame the sidebar merged away, and is not recorded.
+- When no parsed cue covers the live timing, including while a subtitle source is changing or shifted, the strict metadata-free rule applies: a run of identical, contiguous lines each shorter than 0.1s stops being recorded after a few frames. Runs are tracked per line of text, so dual-line karaoke (a kanji and a romaji line frame-flipped together) collapses both lines. Ordinary repeated dialogue, and lines held for a normal beat, always record.
+
+For stats recorded before this, the Vocabulary tab toolbar has a **Duplicates** button:
+
+- Pick how far back to look (7 days, 30 days, 90 days, 1 year, or all time). A narrower window does less work and keeps older history untouched.
+- **Scan** reports the bursts found, the lines they added, and the word and kanji counts they inflated, without writing anything.
+- **Clean Up** applies exactly what the scan reported: each run collapses to its first line (extended to cover the run), and the removed lines' word and kanji occurrences are subtracted from the vocabulary aggregates.
+
+The same thing runs from the terminal:
+
+```bash
+subminer stats cleanup --duplicate-lines --dry-run --lookback-days 30
+subminer stats cleanup --duplicate-lines --lookback-days 30
+```
+
+`--duplicate-lines` (short: `-d`) picks the cleanup mode, so it cannot be combined with `--vocab` or `--lifetime`, and `--dry-run` and `--lookback-days <days>` only apply to it. Omitting `--lookback-days` scans all history; the value must be at least one day.
+
+The cleanup chains runs per line of text, so interleaved dual-line karaoke collapses each of its lines. It also removes the short residue the live rule stores before a run is long enough to recognize: a run one frame short of the usual minimum qualifies when every event is under the strict 0.1s bound.
+
+Runs never cross a session boundary, so rewatching an episode keeps both watches. Session telemetry (watch time, lines seen, tokens seen) and the rollups derived from it are left as recorded: they are cumulative samples taken during playback, and cannot be recomputed for sessions whose raw rows have since been pruned.
+
 ## Retention Defaults
 
 By default, SubMiner keeps all retention tables and raw data (`0` means keep all) while continuing daily/monthly rollup maintenance:

docs-site/launcher-script.md

@@ -151,6 +151,7 @@ subminer stats -b                       # start background stats daemon
 | `subminer stats`                           | Start the stats server (opens the dashboard when `stats.autoOpenBrowser` is on)                   |
 | `subminer stats -b` / `-s`                 | Start/reuse or stop the background stats daemon                                                   |
 | `subminer stats cleanup`                   | Backfill vocabulary metadata and prune stale rows (`-v` vocab, `-l` lifetime summaries)           |
+| `subminer stats cleanup -d`                | Collapse repeated lines from typeset subs (`--dry-run`, `--lookback-days <n>`)                    |
 | `subminer stats rebuild` / `backfill`      | Rebuild or backfill rollup data                                                                   |
 | `subminer doctor`                          | Dependency + config + socket diagnostics (`--refresh-known-words` refreshes the known-word cache) |
 | `subminer settings`                        | Open the SubMiner settings window                                                                 |

docs-site/troubleshooting.md

@@ -171,7 +171,9 @@ Without FFmpeg, card creation still works but audio and image fields will be emp
 
 **Audio or screenshot generation hangs**
 
-Media generation has a 30-second timeout (60 seconds for animated AVIF). If your video file is on a slow network mount or the codec requires software decoding, generation may time out. Try:
+Audio extraction has a 2-minute timeout. SubMiner also limits FFmpeg probing when mpv provides the selected audio stream, which avoids scanning unrelated subtitle and font-attachment streams in large MKV files. Screenshots retain a 30-second timeout, and animated AVIF uses 60 seconds.
+
+If your video file is on a slow or unresponsive network mount, generation may still time out. Try:
 
 - Using a local copy of the video file.
 - Reducing `ankiConnect.media.imageQuality` or switching from `avif` to `static` image type.

docs-site/usage.md

@@ -95,6 +95,8 @@ subminer texthooker               # Texthooker-only mode (-o also opens the brow
 subminer stats -b                 # Start/reuse the background stats daemon
 subminer stats -s                 # Stop the background stats daemon
 subminer stats cleanup            # Backfill vocabulary metadata, prune stale rows
+subminer stats cleanup -d --dry-run  # Preview cleanup of repeated typeset subtitle lines
+subminer stats cleanup -d --lookback-days 30  # Clean only lines recorded in the last 30 days
 subminer stats rebuild            # Rebuild rollup data
 subminer doctor --refresh-known-words  # Refresh the known-word cache
 subminer logs -e                  # Export a sanitized log ZIP and print its path
@@ -107,6 +109,8 @@ subminer app --stop               # Stop the background app
 subminer --version                # Print the launcher's version
 ```
 
+`stats cleanup` runs one mode per invocation: `-v`/`--vocab` (the default), `-l`/`--lifetime`, or `-d`/`--duplicate-lines`; explicitly selected modes cannot be combined. `--dry-run` and `--lookback-days <days>` apply to `--duplicate-lines` only and are rejected without it; `--lookback-days` must be at least one day, and leaving it off scans all history.
+
 Jellyfin, cross-machine sync, and character-dictionary commands have their own sections: [Jellyfin](/jellyfin-integration), [Sync Between Machines](/launcher-script#sync-between-machines), and [Character Dictionary](/character-dictionary).
 
 </details>
@@ -137,7 +141,7 @@ SubMiner.AppImage --start --log-level debug  # Verbose logging without dev mode
 SubMiner.AppImage --help                  # Show all options
 ```
 
-The remaining flags are internal or scripting-only surfaces: the `--jellyfin-*` family (login, library listing, item playback, cast announce), `--sync-cli` (the app's headless sync entrypoint that `subminer sync` proxies to), `--dictionary-candidates` / `--dictionary-select`, and `--playback-feedback <text>`. Run `SubMiner.AppImage --help` for the complete list. The previous `--open-animetosho` flag is still accepted as a deprecated alias for `--open-tsukihime`.
+The remaining flags are internal or scripting-only surfaces: the `--jellyfin-*` family (login, library listing, item playback, cast announce), `--sync-cli` (the app's headless sync entrypoint that `subminer sync` proxies to), the `--stats-cleanup-*` family that `subminer stats cleanup` forwards (`--stats-cleanup-vocab`, `--stats-cleanup-lifetime`, `--stats-cleanup-duplicate-lines`, and its `--stats-cleanup-dry-run` / `--stats-cleanup-lookback-days <days>` modifiers), `--dictionary-candidates` / `--dictionary-select`, and `--playback-feedback <text>`. Run `SubMiner.AppImage --help` for the complete list. The previous `--open-animetosho` flag is still accepted as a deprecated alias for `--open-tsukihime`.
 
 </details>
 

docs/knowledge-base/catalog.md

@@ -3,7 +3,7 @@
 # Documentation Catalog
 
 Status: active  
-Last verified: 2026-05-23  
+Last verified: 2026-08-13
 Owner: Kyle Yasuda  
 Read when: finding internal docs or checking verification status
 
@@ -17,10 +17,10 @@ Read when: finding internal docs or checking verification status
 | KB rules | `docs/knowledge-base/README.md` | active | 2026-05-23 | maintenance policy |
 | Core beliefs | `docs/knowledge-base/core-beliefs.md` | active | 2026-03-13 | agent-first principles |
 | Quality scorecard | `docs/knowledge-base/quality.md` | active | 2026-03-13 | quality grades and gaps |
-| Workflow index | `docs/workflow/README.md` | active | 2026-05-23 | execution map |
+| Workflow index | `docs/workflow/README.md` | active | 2026-08-13 | execution map |
 | Planning guide | `docs/workflow/planning.md` | active | 2026-05-23 | lightweight vs execution plans |
-| Agent plugins | `docs/workflow/agent-plugins.md` | active | 2026-05-23 | repo-local agent workflow plugin ownership |
-| Verification guide | `docs/workflow/verification.md` | active | 2026-05-23 | maintained verification lanes |
+| Agent skills | `docs/workflow/agent-skills.md` | active | 2026-08-13 | repo-local workflow skill ownership |
+| Verification guide | `docs/workflow/verification.md` | active | 2026-08-13 | maintained verification lanes |
 | Release guide | `docs/RELEASING.md` | active | 2026-05-23 | release checklist |
 
 ## Update Rules

docs/superpowers/specs/2026-04-09-library-summary-replaces-per-day-design.md

@@ -1,184 +0,0 @@
-# Library Summary Replaces Per-Day Trends — Design
-
-**Status:** Draft
-**Date:** 2026-04-09
-**Scope:** `stats/` frontend, `src/core/services/immersion-tracker/query-trends.ts` backend
-
-## Problem
-
-The "Library — Per Day" section on the stats Trends tab (`stats/src/components/trends/TrendsTab.tsx:224-254`) renders six stacked-area charts — Videos, Watch Time, Cards, Words, Lookups, and Lookups/100w, each broken down per title per day.
-
-In practice these charts are not useful:
-
-- Most titles only have activity on one or two days in a window, so they render as isolated bumps on a noisy baseline.
-- Stacking 7+ titles with mostly-zero days makes individual lines hard to follow.
-- The top "Activity" and "Period Trends" sections already answer "what am I doing per day" globally.
-- The "Library — Cumulative" section directly below already answers "which titles am I progressing through" with less noise.
-
-The per-day section occupies significant vertical space without carrying its weight, and the user has confirmed it should be replaced.
-
-## Goal
-
-Replace the six per-day stacked charts with a single "Library — Summary" section that surfaces per-title aggregate statistics over the selected date range. The new view should make it trivially easy to answer: "For the selected window, which titles am I spending time on, how much mining output have they produced, and how efficient is my lookup rate on each?"
-
-## Non-goals
-
-- Changing the "Library — Cumulative" section (stays as-is).
-- Changing the "Activity", "Period Trends", or "Patterns" sections.
-- Adding a new API endpoint — the existing dashboard endpoint is extended in place.
-- Renaming internal `anime*` data-model identifiers (`animeId`, `imm_anime`, etc.). Those stay per the convention established in `c5e778d7`; only new fields/types/user-visible strings use generic "title"/"library" wording.
-- Supporting a true all-time library view on the Trends tab. If that's ever wanted, it belongs on a different tab.
-
-## Solution Overview
-
-Delete the "Library — Per Day" section. In its place, add "Library — Summary", composed of:
-
-1. A horizontal-bar leaderboard chart of watch time per title (top 10, descending).
-2. A sortable table of every title with activity in the selected window, with columns: Title, Watch Time, Videos, Sessions, Cards, Words, Lookups, Lookups/100w, Date Range.
-
-Both controls are scoped to the top-of-page date range selector. The existing shared Anime Visibility filter continues to work — it now gates Summary + Cumulative instead of Per-Day + Cumulative.
-
-## Backend
-
-### New type
-
-Add to `stats/src/types/stats.ts` and the backend query module:
-
-```ts
-type LibrarySummaryRow = {
-  title: string;              // display title — anime series, YouTube video title, etc.
-  watchTimeMin: number;       // sum(total_active_min) across the window
-  videos: number;             // distinct video_id count
-  sessions: number;           // session count from imm_sessions
-  cards: number;              // sum(total_cards)
-  words: number;              // sum(total_tokens_seen)
-  lookups: number;            // sum(lookup_count) from imm_sessions
-  lookupsPerHundred: number | null; // lookups / words * 100, null when words == 0
-  firstWatched: number;       // min(rollup_day) as epoch day, within the window
-  lastWatched: number;        // max(rollup_day) as epoch day, within the window
-};
-```
-
-### Query changes in `src/core/services/immersion-tracker/query-trends.ts`
-
-- Add `librarySummary: LibrarySummaryRow[]` to `TrendsDashboardQueryResult`.
-- Populate it from a single aggregating query over `imm_daily_rollups` joined to `imm_videos` → `imm_anime`, filtered by `rollup_day` within the selected window. Session count and lookup count come from `imm_sessions` aggregated by `video_id` and then grouped by the parent library entry. Use a single query (or at most two joined/unioned) — no N+1.
-- `imm_anime` is the generic library-grouping table; anime series, YouTube videos, and yt-dlp imports all land there. The internal table name stays `imm_anime`; only the new field uses generic naming.
-- Return rows pre-sorted by `watchTimeMin` descending so the leaderboard is zero-cost and the table default sort matches.
-- Emit `lookupsPerHundred: null` when `words == 0`.
-
-### Removed from API response
-
-Drop the entire `animePerDay` field from `TrendsDashboardQueryResult` (both backend in `src/core/services/immersion-tracker/query-trends.ts` and frontend in `stats/src/types/stats.ts`).
-
-Internally, the existing helpers (`buildPerAnimeFromDailyRollups`, `buildEpisodesPerAnimeFromDailyRollups`) are still used as intermediates to build `animeCumulative.*` via `buildCumulativePerAnime`. Keep those helpers — just scope their output to local variables inside `getTrendsDashboard` instead of exposing them on the response. The `buildPerAnimeFromSessions` call for lookups and the `buildLookupsPerHundredPerAnime` helper become unused and can be deleted.
-
-Before removing `animePerDay` from the frontend type, verify no other file under `stats/src/` references it. Based on current inspection, only `TrendsTab.tsx` and `stats/src/types/stats.ts` touch it.
-
-## Frontend
-
-### New component: `stats/src/components/trends/LibrarySummarySection.tsx`
-
-Owns the header, leaderboard chart, visibility-filtered data, and the table. Keeps `TrendsTab.tsx` from growing. Component props: `{ rows: LibrarySummaryRow[]; hiddenTitles: ReadonlySet<string>; windowStart: Date; windowEnd: Date }`.
-
-Internal state: `useState<{ column: ColumnId; direction: 'asc' | 'desc' }>` for sort, defaulting to `{ column: 'watchTimeMin', direction: 'desc' }`.
-
-### Layout
-
-Replaces `TrendsTab.tsx:224-254`:
-
-```
-[SectionHeader: "Library — Summary"]
-[AnimeVisibilityFilter — unchanged, shared with Cumulative below]
-[Card, col-span-full: Leaderboard — horizontal bar chart, ~260px tall]
-[Card, col-span-full: Sortable table, auto height up to ~480px with internal scroll]
-```
-
-Both cards use the existing chart/card wrapper styling.
-
-### Leaderboard chart
-
-- Recharts horizontal bar chart (matches the rest of the page — existing charts use `recharts`, not ECharts).
-- Top 10 titles by watch time. If fewer titles have activity, render what's there.
-- Y-axis: title (category), truncated with ellipsis at container width; full title visible in the Recharts tooltip.
-- X-axis: minutes (number).
-- Use `layout="vertical"` with `YAxis dataKey="title" type="category"` and `XAxis type="number"`.
-- Single series color: `#8aadf4` (matching the existing Watch Time color).
-- Reuse `CHART_DEFAULTS`, `CHART_THEME`, `TOOLTIP_CONTENT_STYLE` from `stats/src/lib/chart-theme.ts` so theming matches the rest of the dashboard.
-- Chart order is fixed at watch-time desc regardless of table sort — the leaderboard's meaning is fixed.
-
-### Table
-
-- Plain HTML `<table>` with Tailwind classes. No new deps.
-- Columns, in order:
-  1. **Title** — left-aligned, sticky, truncated with ellipsis, full title on hover.
-  2. **Watch Time** — formatted `Xh Ym` when ≥60 min, else `Xm`.
-  3. **Videos** — integer.
-  4. **Sessions** — integer.
-  5. **Cards** — integer.
-  6. **Words** — integer.
-  7. **Lookups** — integer.
-  8. **Lookups/100w** — one decimal place, `—` when null.
-  9. **Date Range** — `Mon D → Mon D` using the title's `firstWatched` / `lastWatched` within the window.
-- Click a column header to sort; click again to reverse. Visual arrow on the active column.
-- Numeric columns right-aligned.
-- Null `lookupsPerHundred` sorts as the lowest value in both directions (consistent with "no data").
-- Row hover highlight; no row click action (read-only view).
-- Empty state: "No library activity in the selected window."
-
-### Visibility filter integration
-
-Hiding a title via `AnimeVisibilityFilter` removes it from both the leaderboard and the table. The filter's set of available titles is built from the union of titles that appear in `librarySummary` and the existing `animeCumulative.*` arrays (matches current behavior in `buildAnimeVisibilityOptions`).
-
-### `TrendsTab.tsx` changes
-
-- Remove the `filteredEpisodesPerAnime`, `filteredWatchTimePerAnime`, `filteredCardsPerAnime`, `filteredWordsPerAnime`, `filteredLookupsPerAnime`, `filteredLookupsPerHundredPerAnime` locals.
-- Remove the six `<StackedTrendChart>` calls in the "Library — Per Day" section.
-- Remove the `<SectionHeader>Library — Per Day</SectionHeader>` and the `<AnimeVisibilityFilter>` from that position.
-- Insert `<SectionHeader>Library — Summary</SectionHeader>` + `<AnimeVisibilityFilter>` + `<LibrarySummarySection>` in the same place.
-- Update `buildAnimeVisibilityOptions` input to use `librarySummary` titles instead of the six dropped `animePerDay.*` arrays.
-
-## Data flow
-
-1. `useTrends(range, groupBy)` calls `/api/stats/trends/dashboard`.
-2. Response now includes `librarySummary` (sorted by watch time desc).
-3. `TrendsTab` holds the shared `hiddenAnime` set (unchanged).
-4. `LibrarySummarySection` receives `librarySummary` + `hiddenAnime`, filters out hidden rows, renders the leaderboard from the top-10 slice of the filtered list, renders the table from the filtered list with local sort state applied.
-5. Date-range selector changes trigger a new fetch; `groupBy` toggle does not affect the summary section (it's always window-total).
-
-## Edge cases
-
-- **No activity in window:** Section renders header + empty-state card. Leaderboard card hidden. Visibility filter hidden.
-- **One title only:** Leaderboard renders a single bar; table renders one row. No special-casing.
-- **Title with zero words but non-zero lookups:** `lookupsPerHundred` is `null`, rendered as `—`. Sort treats null as lowest.
-- **Title with zero cards/lookups/words but non-zero watch time:** Normal zero rendering, still shown.
-- **Very long titles:** Ellipsis in chart y-axis labels and table title column; full title in `title` attribute / ECharts tooltip.
-- **Mixed sources (anime + YouTube):** No special case — both land in `imm_anime` and are grouped uniformly.
-
-## Testing
-
-### Backend (`query-trends.ts`)
-
-New unit tests, following the existing pattern:
-
-1. Empty window returns `librarySummary: []`.
-2. Single title with a few rollups: all aggregates are correct; `firstWatched`/`lastWatched` match the bounding days within the window.
-3. Multiple titles: rows returned sorted by watch time desc.
-4. Mixed sources (anime-style + YouTube-style entries in `imm_anime`): both appear in the summary with their own aggregates.
-5. Title with `words == 0`: `lookupsPerHundred` is `null`.
-6. Date range excludes some rollups: excluded rollups are not counted; `firstWatched`/`lastWatched` reflect only within-window activity.
-7. `sessions` and `lookups` come from `imm_sessions`, not `imm_daily_rollups`, and are correctly attributed to the parent library entry.
-
-### Frontend
-
-- Existing Trends tab smoke test should continue to pass after wiring.
-- Optional: a targeted render test for `LibrarySummarySection` (empty state, single title, sort toggle, visibility filter interaction). Not required for merge if the smoke test exercises the happy path.
-
-## Release / docs
-
-- One fragment in `changes/*.md` summarizing the replacement.
-- No user-facing docs (`docs-site/`) changes unless the per-day section was documented there — verify during implementation.
-
-## Open items
-
-None.

docs/superpowers/specs/2026-04-09-stats-dashboard-feedback-pass-design.md

@@ -1,347 +0,0 @@
-# Stats Dashboard Feedback Pass — Design
-
-Date: 2026-04-09
-Scope: Stats dashboard UX follow-ups from user feedback (items 1–7).
-Delivery: **Single PR**, broken into logically scoped commits.
-
-## Goals
-
-Address seven concrete pieces of feedback against the Statistics menu:
-
-1. Library — collapse episodes behind a per-series dropdown.
-2. Sessions — roll up multiple sessions of the same episode within a day.
-3. Trends — add a 365d range option.
-4. Library — delete an episode (video) from its detail view.
-5. Vocabulary — tighten spacing between word and reading in the Top 50 table.
-6. Episode detail — hide cards whose Anki notes have been deleted.
-7. Trend/watch charts — add gridlines, fix tick legibility, unify theming.
-
-Out of scope for this pass: English-token ingestion cleanup and Overview stat-card drill-downs (feedback items 8 and 9). Those require a larger design decision and a migration respectively.
-
-## Files touched (inventory)
-
-Dashboard (`stats/src/`):
-- `components/library/LibraryTab.tsx` — collapsible groups (item 1).
-- `components/library/MediaDetailView.tsx`, `components/library/MediaHeader.tsx` — delete-episode action (item 4).
-- `components/sessions/SessionsTab.tsx`, `components/library/MediaSessionList.tsx` — episode rollup (item 2).
-- `components/trends/DateRangeSelector.tsx`, `hooks/useTrends.ts`, `lib/api-client.ts`, `lib/api-client.test.ts` — 365d (item 3).
-- `components/vocabulary/FrequencyRankTable.tsx` — word/reading column collapse (item 5).
-- `components/anime/EpisodeDetail.tsx` — filter deleted Anki cards (item 6).
-- `components/trends/TrendChart.tsx`, `components/trends/StackedTrendChart.tsx`, `components/overview/WatchTimeChart.tsx`, `lib/chart-theme.ts` — chart clarity (item 7).
-- New file: `stats/src/lib/session-grouping.ts` + `session-grouping.test.ts`.
-
-Backend (`src/core/services/`):
-- `immersion-tracker/query-trends.ts` — extend `TrendRange` and `TREND_DAY_LIMITS` (item 3).
-- `immersion-tracker/__tests__/query.test.ts` — 365d coverage (item 3).
-- `stats-server.ts` — passthrough if range validation lives here (check before editing).
-- `__tests__/stats-server.test.ts` — 365d coverage (item 3).
-
-## Commit plan
-
-One PR, one feature per commit. Order picks low-risk mechanical changes first so failures in later commits don't block merging of earlier ones.
-
-1. `feat(stats): add 365d range to trends dashboard` (item 3)
-2. `fix(stats): tighten word/reading column in Top 50 table` (item 5)
-3. `fix(stats): hide cards deleted from Anki in episode detail` (item 6)
-4. `feat(stats): delete episode from library detail view` (item 4)
-5. `feat(stats): collapsible series groups in library` (item 1)
-6. `feat(stats): roll up same-episode sessions within a day` (item 2)
-7. `feat(stats): gridlines and unified theme for trend charts` (item 7)
-
-Each commit must pass `bun run typecheck`, `bun run test:fast`, and any change-specific checks listed below.
-
----
-
-## Item 1 — Library collapsible series groups
-
-### Current behavior
-
-`LibraryTab.tsx` groups media via `groupMediaLibraryItems` and always renders the full grid of `MediaCard`s beneath each group header.
-
-### Target behavior
-
-Each group header becomes clickable. Groups with `items.length > 1` default to **collapsed**; single-video groups stay expanded (collapsing them would be visual noise).
-
-### Implementation
-
-- State: `const [collapsedGroups, setCollapsedGroups] = useState<Set<string>>(...)`. Initialize from `grouped` where `items.length > 1`.
-- Toggle helper: `toggleGroup(key: string)` adds/removes from the set.
-- Group header: wrap in a `<button>` with `aria-expanded` and a chevron icon (`▶`/`▼`). Keep the existing cover + title + subtitle layout inside the button.
-- Children grid is conditionally rendered on `!collapsedGroups.has(group.key)`.
-- Header summary (`N videos · duration · cards`) stays visible in both states so collapsed groups remain informative.
-
-### Tests
-
-- New `LibraryTab.test.tsx` (if not already present — check first) covering:
-  - Multi-video group renders collapsed on first mount.
-  - Single-video group renders expanded on first mount.
-  - Clicking the header toggles visibility.
-  - Header summary is visible in both states.
-
----
-
-## Item 2 — Sessions episode rollup within a day
-
-### Current behavior
-
-`SessionsTab.tsx:10-24` groups sessions by day label only (`formatSessionDayLabel(startedAtMs)`). Multiple sessions of the same episode on the same day show as independent rows. `MediaSessionList.tsx` has the same problem inside the library detail view.
-
-### Target behavior
-
-Within each day, sessions with the same `videoId` collapse into one parent row showing combined totals. A chevron reveals the individual sessions. Single-session buckets render flat (no pointless nesting).
-
-### Implementation
-
-- New helper in `stats/src/lib/session-grouping.ts`:
-  ```ts
-  export interface SessionBucket {
-    key: string;              // videoId as string, or `s-${sessionId}` for singletons
-    videoId: number | null;
-    sessions: SessionSummary[];
-    totalActiveMs: number;
-    totalCardsMined: number;
-    representativeSession: SessionSummary; // most recent, for header display
-  }
-  export function groupSessionsByVideo(sessions: SessionSummary[]): SessionBucket[];
-  ```
-  Sessions missing a `videoId` become singleton buckets.
-
-- `SessionsTab.tsx`: after day grouping, pipe each `daySessions` through `groupSessionsByVideo`. Render each bucket:
-  - `sessions.length === 1`: existing `SessionRow` behavior, unchanged.
-  - `sessions.length >= 2`: render a **bucket row** that looks like `SessionRow` but shows combined totals and session count (e.g. `3 sessions · 1h 24m · 12 cards`). Chevron state stored in a second `Set<string>` on bucket key. Expanded buckets render the child `SessionRow`s indented (`pl-8`) beneath the header.
-- `MediaSessionList.tsx`: within the media detail view, a single video's sessions are all the same `videoId` by definition — grouping here is by day only, and within a day multiple sessions render nested under a day header. Re-use the same visual pattern; factor the bucket row into a shared `SessionBucketRow` component.
-
-### Delete semantics
-
-- Deleting a bucket header offers "Delete all N sessions in this group" (reuse `confirmDayGroupDelete` pattern with a bucket-specific message, or add `confirmBucketDelete`).
-- Deleting an individual session from inside an expanded bucket keeps the existing single-delete flow.
-
-### Tests
-
-- `session-grouping.test.ts`:
-  - Empty input → empty output.
-  - All unique videos → N singleton buckets.
-  - Two sessions same videoId → one bucket with correct totals and representative (most recent start time).
-  - Missing videoId → singleton bucket keyed by sessionId.
-- `SessionsTab.test.tsx` (extend or add) verifying the rendered bucket rows expand/collapse and delete hooks fire with the right ID set.
-
----
-
-## Item 3 — 365d trends range
-
-### Backend
-
-`src/core/services/immersion-tracker/query-trends.ts`:
-- `type TrendRange = '7d' | '30d' | '90d' | '365d' | 'all';`
-- Add `'365d': 365` to `TREND_DAY_LIMITS`.
-- `getTrendDayLimit` picks up the new key automatically because of the `Exclude<TrendRange, 'all'>` generic.
-
-`src/core/services/stats-server.ts`:
-- Search for any hardcoded range validation (e.g. allow-list in the trends route handler) and extend it.
-
-### Frontend
-
-- `hooks/useTrends.ts`: widen the `TimeRange` union.
-- `components/trends/DateRangeSelector.tsx`: add `'365d'` to the options list. Display label stays as `365d`.
-- `lib/api-client.ts` / `api-client.test.ts`: if the client validates ranges, add `365d`.
-
-### Tests
-
-- `query.test.ts`: extend the existing range table to cover `365d` returning 365 days of data.
-- `stats-server.test.ts`: ensure the route accepts `range=365d`.
-- `api-client.test.ts`: ensure the client emits the new range.
-
-### Change-specific checks
-
-- `bun run test:config` is not required here (no schema/defaults change).
-- Run `bun run typecheck` + `bun run test:fast`.
-
----
-
-## Item 4 — Delete episode from library detail
-
-### Current behavior
-
-`MediaDetailView.tsx` provides session-level delete only. The backend `deleteVideo` exists (`query-maintenance.ts:509`), the API is exposed at `stats-server.ts:559`, and `api-client.deleteVideo` is already wired (`stats/src/lib/api-client.ts:146`). `EpisodeList.tsx:46` already uses it from the anime tab.
-
-### Target behavior
-
-A "Delete Episode" action in `MediaHeader` (top-right, small, `text-ctp-red`), gated by `confirmEpisodeDelete(title)`. On success, call `onBack()` and make sure the parent `LibraryTab` refetches.
-
-### Implementation
-
-- Add an `onDeleteEpisode?: () => void` prop to `MediaHeader` and render the button only if provided.
-- In `MediaDetailView`:
-  - New handler `handleDeleteEpisode` that calls `apiClient.deleteVideo(videoId)`, then `onBack()`.
-  - Reuse `confirmEpisodeDelete` from `stats/src/lib/delete-confirm.ts`.
-- In `LibraryTab`:
-  - `useMediaLibrary` returns fresh data on mount. The simplest fix: pass a `refresh` function from the hook (extend the hook if it doesn't already expose one) and call it when the detail view signals back.
-  - Alternative: force a remount by incrementing a `libraryVersion` key on the library list. Prefer `refresh` for clarity.
-
-### Tests
-
-- Extend the existing `MediaDetailView.test.tsx`: mock `apiClient.deleteVideo`, click the new button, confirm `onBack` fires after success.
-- `useMediaLibrary.test.ts`: if we add a `refresh` method, cover it.
-
----
-
-## Item 5 — Vocabulary word/reading column collapse
-
-### Current behavior
-
-`FrequencyRankTable.tsx:110-144` uses a 5-column table: `Rank | Word | Reading | POS | Seen`. Word and Reading are auto-sized, producing a large gap.
-
-### Target behavior
-
-Merge Word + Reading into a single column titled "Word". Reading sits immediately after the headword in a muted, smaller style.
-
-### Implementation
-
-- Drop the `<th>Reading</th>` header and cell.
-- Word cell becomes:
-  ```tsx
-  <td className="py-1.5 pr-3">
-    <span className="text-ctp-text font-medium">{w.headword}</span>
-    {reading && (
-      <span className="text-ctp-subtext0 text-xs ml-1.5">
-        【{reading}】
-      </span>
-    )}
-  </td>
-  ```
-  where `reading = fullReading(w.headword, w.reading)` and differs from `headword`.
-- Keep `fullReading` import from `reading-utils`.
-
-### Tests
-
-- Extend `FrequencyRankTable.test.tsx` (if present — otherwise add a focused test) to assert:
-  - Headword renders.
-  - Reading renders when different from headword.
-  - Reading does not render when equal to headword.
-
----
-
-## Item 6 — Hide Anki-deleted cards in Cards Mined
-
-### Current behavior
-
-`EpisodeDetail.tsx:109-147` iterates `cardEvents`, fetches note info via `ankiNotesInfo(allNoteIds)`, and for each `noteId` renders a row even if no matching `info` came back — the user sees an empty word with an "Open in Anki" button that leads nowhere.
-
-### Target behavior
-
-After `ankiNotesInfo` resolves:
-- Drop `noteId`s that are not in the resolved map.
-- Drop `cardEvents` whose `noteIds` list was non-empty but is now empty after filtering.
-- Card events with a positive `cardsDelta` but no `noteIds` (legacy rollup path) still render as `+N cards` — we have no way to cross-reference them, so leave them alone.
-
-### Implementation
-
-- Compute `filteredCardEvents` as a `useMemo` depending on `data.cardEvents` and `noteInfos`.
-- Iterate `filteredCardEvents` instead of `cardEvents` in the render.
-- Surface a subtle note (optional, muted) "N cards hidden (deleted from Anki)" at the end of the list if any were filtered — helps the user understand why counts here diverge from session totals. Final decision on the note can be made at PR review; default: **show it**.
-
-### Tests
-
-- Add a test in `EpisodeDetail.test.tsx` (add the file if not present) that stubs `ankiNotesInfo` to return only a subset of notes and verifies the missing ones are not rendered.
-
-### Other call sites
-
-- Grep so far shows `ankiNotesInfo` is only used in `EpisodeDetail.tsx`. Re-verify before landing the commit; if another call site appears, apply the same filter.
-
----
-
-## Item 7 — Trend/watch chart clarity pass
-
-### Current behavior
-
-`TrendChart.tsx`, `StackedTrendChart.tsx`, and `WatchTimeChart.tsx` render Recharts components with:
-- No `CartesianGrid` → no horizontal reference lines.
-- 9px axis ticks → borderline unreadable.
-- Height 120 → cramped.
-- Tooltip uses raw labels (`04/04` etc.).
-- No shared theme object; each chart redefines colors and tooltip styles inline.
-
-`stats/src/lib/chart-theme.ts` already exists and currently exports a single `CHART_THEME` constant with tick/tooltip colors and `barFill`. It will be extended, not replaced, to preserve existing consumers.
-
-### Target behavior
-
-All three charts share a theme, have horizontal gridlines, readable ticks, and sensible tooltips.
-
-### Implementation
-
-Extend `stats/src/lib/chart-theme.ts` with the additional shared defaults (keeping the existing `CHART_THEME` export intact so current consumers don't break):
-```ts
-export const CHART_THEME = {
-  tick: '#a5adcb',
-  tooltipBg: '#363a4f',
-  tooltipBorder: '#494d64',
-  tooltipText: '#cad3f5',
-  tooltipLabel: '#b8c0e0',
-  barFill: '#8aadf4',
-  grid: '#494d64',
-  axisLine: '#494d64',
-} as const;
-
-export const CHART_DEFAULTS = {
-  height: 160,
-  tickFontSize: 11,
-  margin: { top: 8, right: 8, bottom: 0, left: 0 },
-  grid: { strokeDasharray: '3 3', vertical: false },
-} as const;
-
-export const TOOLTIP_CONTENT_STYLE = {
-  background: CHART_THEME.tooltipBg,
-  border: `1px solid ${CHART_THEME.tooltipBorder}`,
-  borderRadius: 6,
-  color: CHART_THEME.tooltipText,
-  fontSize: 12,
-};
-```
-
-Apply to each chart:
-- Import `CartesianGrid` from recharts.
-- Insert `<CartesianGrid stroke={CHART_THEME.grid} {...CHART_DEFAULTS.grid} />` inside each chart container.
-- `<XAxis tick={{ fontSize: CHART_DEFAULTS.tickFontSize, fill: CHART_THEME.tick }} />` and equivalent `YAxis`.
-- `YAxis` gains `axisLine={{ stroke: CHART_THEME.axisLine }}`.
-- `ResponsiveContainer` height changes from 120 → `CHART_DEFAULTS.height`.
-- `Tooltip` `contentStyle` uses `TOOLTIP_CONTENT_STYLE`, and charts pass a `labelFormatter` when the label is a date key (e.g. show `Fri Apr 4`).
-
-### Unit formatters
-
-- `TrendChart` already accepts a `formatter` prop — extend usage sites to pass unit-aware formatters where they aren't already (`formatDuration`, `formatNumber`, etc.).
-
-### Tests
-
-- `chart-theme.test.ts` (if present — otherwise add a trivial snapshot to keep the shape stable).
-- `TrendChart` snapshot/render tests: no regression, gridline element present.
-
----
-
-## Verification gate
-
-Before requesting code review, run:
-
-```
-bun run typecheck
-bun run test:fast
-bun run test:env
-bun run test:runtime:compat   # dist-sensitive check for the charts
-bun run build
-bun run test:smoke:dist
-```
-
-No docs-site changes are planned in this spec; if `docs-site/` ends up touched (e.g. screenshots), also run `bun run docs:test` and `bun run docs:build`.
-
-No config schema changes → `bun run test:config` and `bun run generate:config-example` are not required.
-
-## Risks and open questions
-
-- **MediaDetailView refresh**: `useMediaLibrary` may not expose a `refresh` function. If it doesn't, the simplest path is adding one; the alternative (keying a remount) works but is harder to test. Decide during implementation.
-- **Session bucket delete UX**: "Delete all N sessions in this group" is powerful. The copy must make it clear the underlying sessions are being removed, not just the grouping. Reuse `confirmBucketDelete` wording from existing confirm helpers if possible.
-- **Anki-deleted-cards hidden notice**: Showing a subtle "N cards hidden" footer is a call that can be made at PR review.
-- **Bucket delete helper**: `confirmBucketDelete` does not currently exist in `delete-confirm.ts`. Implementation either adds it or reuses `confirmDayGroupDelete` with bucket-specific wording — decide during the session-rollup commit.
-
-## Changelog entry
-
-User-visible PR → needs a fragment under `changes/*.md`. Suggested title:
-`Stats dashboard: collapsible series, session rollups, 365d trends, chart polish, episode delete.`

docs/workflow/README.md

@@ -3,7 +3,7 @@
 # Workflow
 
 Status: active  
-Last verified: 2026-05-23  
+Last verified: 2026-08-13
 Owner: Kyle Yasuda  
 Read when: planning or executing nontrivial work in this repo
 
@@ -13,7 +13,7 @@ This section is the internal workflow map for contributors and agents.
 
 - [Planning](./planning.md) - when to write a lightweight plan vs a full execution plan
 - [Verification](./verification.md) - maintained test/build lanes and handoff gate
-- [Agent Plugins](./agent-plugins.md) - repo-local plugin ownership for agent workflow skills
+- [Agent Skills](./agent-skills.md) - repo-local workflow skill ownership
 - [Release Guide](../RELEASING.md) - tagged release workflow
 
 ## Default Flow

docs/workflow/agent-plugins.md

@@ -1,27 +0,0 @@
-<!-- read_when: using or modifying repo-local agent plugins -->
-
-# Agent Plugins
-
-Status: active
-Last verified: 2026-05-23
-Owner: Kyle Yasuda
-Read when: packaging or migrating repo-local agent workflow skills into plugins
-
-## SubMiner Workflow Plugin
-
-- Canonical plugin path: `plugins/subminer-workflow/`
-- Marketplace catalog: `.agents/plugins/marketplace.json`
-- Canonical skill sources:
-  - `plugins/subminer-workflow/skills/subminer-scrum-master/`
-  - `plugins/subminer-workflow/skills/subminer-change-verification/`
-
-## Migration Rule
-
-- Plugin-owned skills are the source of truth.
-- `.agents/skills/subminer-*` remain only as compatibility shims.
-- Existing script entrypoints under `.agents/skills/subminer-change-verification/scripts/` stay as wrappers so historical commands do not break.
-
-## Verification
-
-- For plugin/docs-only changes, start with `bun run test:docs:kb`.
-- Use the plugin-owned verifier when the change crosses from docs into scripts or workflow logic.

docs/workflow/agent-skills.md

@@ -0,0 +1,31 @@
+<!-- read_when: using or modifying repo-local agent skills -->
+
+# Agent Skills
+
+Status: active
+Last verified: 2026-08-13
+Owner: Kyle Yasuda
+Read when: using, adding, or changing a repo-local agent workflow skill
+
+## Canonical Skills
+
+- `.agents/skills/subminer-change-verification/`
+  - Selects the cheapest sufficient repo-native verification lane.
+  - Defers command ownership to `package.json` and `docs/workflow/verification.md`.
+
+Repo-local workflows stay as standalone skills. Do not add plugin packaging, marketplace metadata, or compatibility shims unless the workflow is intentionally being distributed beyond this repository.
+
+## Rules
+
+- Keep each skill focused on one repeatable repository task.
+- Prefer instructions over helper scripts unless deterministic tooling provides clear value beyond existing package commands.
+- Keep trigger descriptions narrow enough to avoid invoking skills for unrelated requests.
+- Update this page and the documentation catalog when skill ownership changes.
+
+## Verification
+
+For skill or internal workflow documentation changes, run:
+
+```bash
+bun run test:docs:kb
+```

docs/workflow/verification.md

@@ -3,14 +3,14 @@
 # Verification
 
 Status: active  
-Last verified: 2026-07-06  
+Last verified: 2026-08-13
 Owner: Kyle Yasuda  
 Read when: selecting the right verification lane for a change
 
 ## Lane Infrastructure
 
 - Lane membership is defined once in `scripts/test-lanes.ts` and discovered by
-  directory — new test files join their lane automatically; never hand-list test
+  directory, so new test files join their lane automatically; never hand-list test
   files in `package.json`.
 - `scripts/run-test-lane.mjs` runs each test file in its own `bun test` process
   (per-file isolation with a wall timeout) so a hanging test or leaked global in
@@ -43,8 +43,8 @@ bun run docs:build
 
 ## Cheap-First Lane Selection
 
-- Docs-only boundary/content changes: `bun run docs:test`, `bun run docs:build`
-- Internal KB / `AGENTS.md` changes: `bun run test:docs:kb`
+- User-facing `docs-site/` changes: `bun run docs:test`, `bun run docs:build`
+- Internal KB, `AGENTS.md`, or `.agents/skills/**` changes: `bun run test:docs:kb`
 - Config/schema/defaults: `bun run test:config`, then `bun run generate:config-example` if template/defaults changed
 - Launcher/plugin: `bun run test:launcher` or `bun run test:env`
 - Runtime-compat / compiled behavior: `bun run test:runtime:compat`

launcher/commands/stats-command.ts

@@ -157,6 +157,15 @@ export async function runStatsCommand(
     if (args.statsCleanupLifetime) {
       forwarded.push('--stats-cleanup-lifetime');
     }
+    if (args.statsCleanupDuplicateLines) {
+      forwarded.push('--stats-cleanup-duplicate-lines');
+    }
+    if (args.statsCleanupDryRun) {
+      forwarded.push('--stats-cleanup-dry-run');
+    }
+    if (args.statsCleanupLookbackDays) {
+      forwarded.push('--stats-cleanup-lookback-days', String(args.statsCleanupLookbackDays));
+    }
     if (shouldForwardLogLevel(args.logLevel)) {
       forwarded.push('--log-level', args.logLevel);
     }

launcher/config/args-normalizer.test.ts

@@ -134,6 +134,9 @@ test('applyInvocationsToArgs maps config and jellyfin invocation state', () => {
     statsCleanup: false,
     statsCleanupVocab: false,
     statsCleanupLifetime: false,
+    statsCleanupDuplicateLines: false,
+    statsCleanupDryRun: false,
+    statsCleanupLookbackDays: null,
     statsLogLevel: null,
     syncTriggered: false,
     syncCliTokens: [],
@@ -185,6 +188,9 @@ test('applyInvocationsToArgs maps settings invocation to settings window', () =>
     statsCleanup: false,
     statsCleanupVocab: false,
     statsCleanupLifetime: false,
+    statsCleanupDuplicateLines: false,
+    statsCleanupDryRun: false,
+    statsCleanupLookbackDays: null,
     statsLogLevel: null,
     syncTriggered: false,
     syncCliTokens: [],
@@ -229,6 +235,9 @@ test('applyInvocationsToArgs fails when config invocation has no action', () =>
       statsCleanup: false,
       statsCleanupVocab: false,
       statsCleanupLifetime: false,
+      statsCleanupDuplicateLines: false,
+      statsCleanupDryRun: false,
+      statsCleanupLookbackDays: null,
       statsLogLevel: null,
       syncTriggered: false,
       syncCliTokens: [],
@@ -271,6 +280,9 @@ test('applyInvocationsToArgs maps texthooker browser-open request', () => {
     statsCleanup: false,
     statsCleanupVocab: false,
     statsCleanupLifetime: false,
+    statsCleanupDuplicateLines: false,
+    statsCleanupDryRun: false,
+    statsCleanupLookbackDays: null,
     statsLogLevel: null,
     syncTriggered: false,
     syncCliTokens: [],

launcher/config/args-normalizer.ts

@@ -162,6 +162,8 @@ export function createDefaultArgs(
     statsCleanup: false,
     statsCleanupVocab: false,
     statsCleanupLifetime: false,
+    statsCleanupDuplicateLines: false,
+    statsCleanupDryRun: false,
     doctor: false,
     doctorRefreshKnownWords: false,
     logsExport: false,
@@ -258,6 +260,11 @@ export function applyInvocationsToArgs(parsed: Args, invocations: CliInvocations
   if (invocations.statsCleanup) parsed.statsCleanup = true;
   if (invocations.statsCleanupVocab) parsed.statsCleanupVocab = true;
   if (invocations.statsCleanupLifetime) parsed.statsCleanupLifetime = true;
+  if (invocations.statsCleanupDuplicateLines) parsed.statsCleanupDuplicateLines = true;
+  if (invocations.statsCleanupDryRun) parsed.statsCleanupDryRun = true;
+  if (invocations.statsCleanupLookbackDays !== null) {
+    parsed.statsCleanupLookbackDays = invocations.statsCleanupLookbackDays;
+  }
   if (invocations.dictionaryTarget) {
     parsed.dictionaryTarget = parseDictionaryTarget(invocations.dictionaryTarget);
   } else if (

launcher/config/cli-parser-builder.ts

@@ -37,6 +37,9 @@ export interface CliInvocations {
   statsCleanup: boolean;
   statsCleanupVocab: boolean;
   statsCleanupLifetime: boolean;
+  statsCleanupDuplicateLines: boolean;
+  statsCleanupDryRun: boolean;
+  statsCleanupLookbackDays: number | null;
   statsLogLevel: string | null;
   syncTriggered: boolean;
   syncCliTokens: string[];
@@ -53,6 +56,16 @@ export interface CliInvocations {
   texthookerOpenBrowser: boolean;
 }
 
+/** `--lookback-days` narrows the duplicate-line cleanup; fractions are floored. */
+function parseStatsLookbackDays(value: unknown): number | null {
+  if (typeof value !== 'string' && typeof value !== 'number') return null;
+  const days = Number(value);
+  if (!Number.isFinite(days) || days < 1) {
+    throw new Error('Stats --lookback-days must be at least one day.');
+  }
+  return Math.floor(days);
+}
+
 function applyRootOptions(program: Command): void {
   program
     .option(
@@ -169,6 +182,9 @@ export function parseCliPrograms(
   let statsCleanup = false;
   let statsCleanupVocab = false;
   let statsCleanupLifetime = false;
+  let statsCleanupDuplicateLines = false;
+  let statsCleanupDryRun = false;
+  let statsCleanupLookbackDays: number | null = null;
   let statsLogLevel: string | null = null;
   let syncTriggered = false;
   let syncCliTokens: string[] = [];
@@ -269,6 +285,9 @@ export function parseCliPrograms(
     .option('-s, --stop', 'Stop the background stats server')
     .option('-v, --vocab', 'Clean vocabulary rows in the stats database')
     .option('-l, --lifetime', 'Rebuild lifetime summary rows from retained data')
+    .option('-d, --duplicate-lines', 'Collapse repeated subtitle lines from typeset animations')
+    .option('--dry-run', 'Report what a cleanup would remove without changing anything')
+    .option('--lookback-days <days>', 'Only clean lines recorded in the last N days')
     .option('--log-level <level>', 'Log level')
     .action((action: string | undefined, options: Record<string, unknown>) => {
       statsTriggered = true;
@@ -289,13 +308,35 @@ export function parseCliPrograms(
       if (normalizedAction && (statsBackground || statsStop)) {
         throw new Error('Stats background and stop flags cannot be combined with stats actions.');
       }
-      if (normalizedAction !== 'cleanup' && (options.vocab === true || options.lifetime === true)) {
-        throw new Error('Stats --vocab and --lifetime flags require the cleanup action.');
+      if (
+        normalizedAction !== 'cleanup' &&
+        (options.vocab === true || options.lifetime === true || options.duplicateLines === true)
+      ) {
+        throw new Error(
+          'Stats --vocab, --lifetime and --duplicate-lines flags require the cleanup action.',
+        );
+      }
+      if (
+        options.duplicateLines !== true &&
+        (options.dryRun === true || options.lookbackDays !== undefined)
+      ) {
+        throw new Error('Stats --dry-run and --lookback-days require --duplicate-lines.');
       }
       if (normalizedAction === 'cleanup') {
         statsCleanup = true;
         statsCleanupLifetime = options.lifetime === true;
-        statsCleanupVocab = statsCleanupLifetime ? false : options.vocab !== false;
+        statsCleanupDuplicateLines = options.duplicateLines === true;
+        const explicitModeCount = [options.vocab, options.lifetime, options.duplicateLines].filter(
+          (value) => value === true,
+        ).length;
+        if (explicitModeCount > 1) {
+          throw new Error('Stats cleanup runs one mode at a time.');
+        }
+        // Vocabulary cleanup stays the default so `stats cleanup` keeps its old meaning.
+        statsCleanupVocab =
+          statsCleanupLifetime || statsCleanupDuplicateLines ? false : options.vocab !== false;
+        statsCleanupDryRun = options.dryRun === true;
+        statsCleanupLookbackDays = parseStatsLookbackDays(options.lookbackDays);
       } else if (normalizedAction === 'rebuild' || normalizedAction === 'backfill') {
         statsCleanup = true;
         statsCleanupLifetime = true;
@@ -483,6 +524,9 @@ export function parseCliPrograms(
       statsCleanup,
       statsCleanupVocab,
       statsCleanupLifetime,
+      statsCleanupDuplicateLines,
+      statsCleanupDryRun,
+      statsCleanupLookbackDays,
       statsLogLevel,
       syncTriggered,
       syncCliTokens,

launcher/parse-args.test.ts

@@ -232,6 +232,75 @@ test('parseArgs maps lifetime stats cleanup flag', () => {
   assert.equal(parsed.statsCleanupLifetime, true);
 });
 
+test('parseArgs maps duplicate-line stats cleanup flags', () => {
+  const parsed = parseArgs(
+    ['stats', 'cleanup', '--duplicate-lines', '--dry-run', '--lookback-days', '30'],
+    'subminer',
+    {},
+  );
+
+  assert.equal(parsed.statsCleanup, true);
+  assert.equal(parsed.statsCleanupVocab, false);
+  assert.equal(parsed.statsCleanupDuplicateLines, true);
+  assert.equal(parsed.statsCleanupDryRun, true);
+  assert.equal(parsed.statsCleanupLookbackDays, 30);
+
+  const fractional = parseArgs(
+    ['stats', 'cleanup', '--duplicate-lines', '--lookback-days', '1.5'],
+    'subminer',
+    {},
+  );
+  assert.equal(fractional.statsCleanupLookbackDays, 1);
+});
+
+test('parseArgs rejects duplicate-line flags without the duplicate-lines mode', () => {
+  const error = withProcessExitIntercept(() => {
+    parseArgs(['stats', 'cleanup', '--dry-run'], 'subminer', {});
+  });
+
+  assert.equal(error.code, 1);
+  assert.match(error.stderr, /--dry-run and --lookback-days require --duplicate-lines/);
+});
+
+test('parseArgs rejects an empty lookback value outside duplicate-line cleanup', () => {
+  const error = withProcessExitIntercept(() => {
+    parseArgs(['stats', '--lookback-days', ''], 'subminer', {});
+  });
+
+  assert.equal(error.code, 1);
+  assert.match(error.stderr, /--dry-run and --lookback-days require --duplicate-lines/);
+});
+
+test('parseArgs rejects combining explicit cleanup modes', () => {
+  for (const modes of [
+    ['--lifetime', '--duplicate-lines'],
+    ['--vocab', '--duplicate-lines'],
+    ['--vocab', '--lifetime'],
+  ]) {
+    const error = withProcessExitIntercept(() => {
+      parseArgs(['stats', 'cleanup', ...modes], 'subminer', {});
+    });
+
+    assert.equal(error.code, 1);
+    assert.match(error.stderr, /Stats cleanup runs one mode at a time/);
+  }
+});
+
+test('parseArgs rejects unusable lookback windows', () => {
+  for (const value of ['0', '0.5', '-5', 'soon']) {
+    const error = withProcessExitIntercept(() => {
+      parseArgs(
+        ['stats', 'cleanup', '--duplicate-lines', '--lookback-days', value],
+        'subminer',
+        {},
+      );
+    });
+
+    assert.equal(error.code, 1);
+    assert.match(error.stderr, /--lookback-days must be at least one day/);
+  }
+});
+
 test('parseArgs rejects cleanup-only stats flags without cleanup action', () => {
   const error = withProcessExitIntercept(() => {
     parseArgs(['stats', '--vocab'], 'subminer', {});
@@ -239,7 +308,10 @@ test('parseArgs rejects cleanup-only stats flags without cleanup action', () =>
 
   assert.equal(error.code, 1);
   assert.match(error.message, /exit:1/);
-  assert.match(error.stderr, /Stats --vocab and --lifetime flags require the cleanup action/);
+  assert.match(
+    error.stderr,
+    /Stats --vocab, --lifetime and --duplicate-lines flags require the cleanup action/,
+  );
 });
 
 test('parseArgs maps stats rebuild action to cleanup lifetime mode', () => {

launcher/types.ts

@@ -142,6 +142,9 @@ export interface Args {
   statsCleanup?: boolean;
   statsCleanupVocab?: boolean;
   statsCleanupLifetime?: boolean;
+  statsCleanupDuplicateLines?: boolean;
+  statsCleanupDryRun?: boolean;
+  statsCleanupLookbackDays?: number;
   dictionaryTarget?: string;
   doctor: boolean;
   doctorRefreshKnownWords: boolean;

plugins/subminer-workflow/.codex-plugin/plugin.json

@@ -1,30 +0,0 @@
-{
-  "name": "subminer-workflow",
-  "version": "0.1.0",
-  "description": "Repo-local SubMiner agent workflow plugin for orchestration and change verification.",
-  "author": {
-    "name": "Kyle Yasuda",
-    "email": "suda@sudacode.com",
-    "url": "https://github.com/sudacode"
-  },
-  "homepage": "https://github.com/sudacode/SubMiner/tree/main/plugins/subminer-workflow",
-  "repository": "https://github.com/sudacode/SubMiner",
-  "license": "GPL-3.0-or-later",
-  "keywords": ["subminer", "workflow", "verification", "skills"],
-  "skills": "./skills/",
-  "interface": {
-    "displayName": "SubMiner Workflow",
-    "shortDescription": "SubMiner orchestration and verification.",
-    "longDescription": "Canonical repo-local plugin for SubMiner agent workflow packaging. Owns the scrum-master and change-verification skills plus helper scripts used to plan, verify, and validate changes reproducibly inside this repo.",
-    "developerName": "Kyle Yasuda",
-    "category": "Productivity",
-    "capabilities": ["Interactive", "Write"],
-    "websiteURL": "https://github.com/sudacode/SubMiner",
-    "defaultPrompt": [
-      "Use SubMiner workflow to plan and ship a feature.",
-      "Verify a SubMiner change with the plugin-owned verifier.",
-      "Plan and ship this SubMiner task."
-    ],
-    "brandColor": "#2F6B4F"
-  }
-}

plugins/subminer-workflow/README.md

@@ -1,40 +0,0 @@
-<!-- read_when: migrating or using the repo-local SubMiner workflow plugin -->
-
-# SubMiner Workflow Plugin
-
-Status: active
-Last verified: 2026-03-26
-Owner: Kyle Yasuda
-Read when: using or updating the repo-local plugin that owns SubMiner agent workflow skills
-
-This plugin is the canonical source of truth for the SubMiner agent workflow packaging.
-
-## Contents
-
-- `skills/subminer-scrum-master/`
-  - intake, planning, dispatch, and handoff workflow
-- `skills/subminer-change-verification/`
-  - cheap-first verification workflow plus helper scripts
-
-## Compatibility
-
-- `.agents/skills/subminer-scrum-master/` is a compatibility shim that redirects to the plugin-owned skill.
-- `.agents/skills/subminer-change-verification/` is a compatibility shim.
-- `.agents/skills/subminer-change-verification/scripts/*.sh` remain as wrapper entrypoints so existing docs and shell history keep working.
-
-## Verification
-
-For plugin/doc/shim changes, prefer:
-
-```bash
-bun run test:docs:kb
-bash plugins/subminer-workflow/skills/subminer-change-verification/scripts/verify_subminer_change.sh --lane docs --lane core \
-  plugins/subminer-workflow \
-  .agents/skills/subminer-scrum-master/SKILL.md \
-  .agents/skills/subminer-change-verification/SKILL.md \
-  .agents/skills/subminer-change-verification/scripts/classify_subminer_diff.sh \
-  .agents/skills/subminer-change-verification/scripts/verify_subminer_change.sh \
-  .agents/plugins/marketplace.json \
-  docs/workflow/README.md \
-  docs/workflow/agent-plugins.md
-```

plugins/subminer-workflow/skills/subminer-change-verification/SKILL.md

@@ -1,143 +0,0 @@
----
-name: 'subminer-change-verification'
-description: 'Use when working in the SubMiner repo and you need to verify code changes actually work. Covers targeted regression checks during debugging and pre-handoff verification, with cheap-first lane selection for config, docs, launcher/plugin, runtime-compat, and optional real-runtime escalation.'
----
-
-# SubMiner Change Verification
-
-Canonical source: this plugin path.
-
-Use this skill for SubMiner code changes. Default to cheap, repo-native verification first. Escalate only when the changed behavior actually depends on Electron, mpv, overlay/window tracking, or other GUI-sensitive runtime behavior.
-
-## Scripts
-
-- `scripts/classify_subminer_diff.sh`
-  - Emits suggested lanes and flags from explicit paths or current git changes.
-- `scripts/verify_subminer_change.sh`
-  - Runs selected lanes, captures artifacts, and writes a compact summary.
-
-If you need an explicit installed path, use the directory that contains this `SKILL.md`. The helper scripts live under:
-
-```bash
-export SUBMINER_VERIFY_SKILL="<path-to-plugin-skill>"
-```
-
-## Default workflow
-
-1. Inspect the changed files or user-requested area.
-2. Run the classifier unless you already know the right lane.
-3. Run the verifier with the cheapest sufficient lane set.
-4. If the classifier emits `flag:real-runtime-candidate`, do not jump straight to runtime verification. First run the non-runtime lanes.
-5. Escalate to explicit `--lane real-runtime --allow-real-runtime` only when cheaper lanes cannot validate the behavior claim.
-6. Return:
-   - verification summary
-   - exact commands run
-   - artifact paths
-   - skipped lanes and blockers
-
-## Quick start
-
-Plugin-source quick start:
-
-```bash
-bash plugins/subminer-workflow/skills/subminer-change-verification/scripts/classify_subminer_diff.sh
-```
-
-Installed-skill quick start:
-
-```bash
-bash "$SUBMINER_VERIFY_SKILL/scripts/classify_subminer_diff.sh"
-```
-
-Compatibility entrypoint:
-
-```bash
-bash .agents/skills/subminer-change-verification/scripts/classify_subminer_diff.sh
-```
-
-Classify explicit files:
-
-```bash
-bash plugins/subminer-workflow/skills/subminer-change-verification/scripts/classify_subminer_diff.sh \
-  launcher/main.ts \
-  plugin/subminer/lifecycle.lua \
-  src/main/runtime/mpv-client-runtime-service.ts
-```
-
-Run automatic lane selection:
-
-```bash
-bash plugins/subminer-workflow/skills/subminer-change-verification/scripts/verify_subminer_change.sh
-```
-
-Installed-skill form:
-
-```bash
-bash "$SUBMINER_VERIFY_SKILL/scripts/verify_subminer_change.sh"
-```
-
-Compatibility entrypoint:
-
-```bash
-bash .agents/skills/subminer-change-verification/scripts/verify_subminer_change.sh
-```
-
-Run targeted lanes:
-
-```bash
-bash plugins/subminer-workflow/skills/subminer-change-verification/scripts/verify_subminer_change.sh \
-  --lane launcher-plugin \
-  --lane runtime-compat
-```
-
-Dry-run to inspect planned commands and artifact layout:
-
-```bash
-bash plugins/subminer-workflow/skills/subminer-change-verification/scripts/verify_subminer_change.sh \
-  --dry-run \
-  launcher/main.ts \
-  src/main.ts
-```
-
-## Lane guidance
-
-- `docs`
-  - For `docs-site/`, `docs/`, and doc-only edits.
-- `config`
-  - For `src/config/` and config-template-sensitive edits.
-- `stats`
-  - For `stats/` dashboard UI edits.
-- `core`
-  - For general source changes where `typecheck` + `test:fast` is the best cheap signal.
-- `launcher-plugin`
-  - For `launcher/`, `plugin/subminer/`, plugin gating scripts, and wrapper/mpv routing work.
-- `runtime-compat`
-  - For `src/main*`, runtime/composer wiring, mpv/overlay services, window trackers, and dist-sensitive behavior.
-- `real-runtime`
-  - Only after deliberate escalation.
-
-## Real Runtime Escalation
-
-Escalate only when the change claim depends on actual runtime behavior, for example:
-
-- overlay appears, hides, or tracks a real mpv window
-- mpv launch flags or pause-until-ready behavior
-- plugin/socket/auto-start handshake under a real player
-- macOS/window-tracker/focus-sensitive behavior
-
-If the environment cannot support authoritative runtime verification, report the blocker explicitly. Do not silently downgrade a runtime-required claim to a pass.
-
-## Artifact contract
-
-The verifier writes under `.tmp/skill-verification/<timestamp>/`:
-
-- `summary.json`
-- `summary.txt`
-- `classification.txt`
-- `env.txt`
-- `lanes.txt`
-- `steps.tsv`
-- `steps/*.stdout.log`
-- `steps/*.stderr.log`
-
-On failure, quote the exact failing command and point at the artifact directory.

plugins/subminer-workflow/skills/subminer-change-verification/scripts/classify_subminer_diff.sh

@@ -1,171 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-usage() {
-  cat <<'EOF'
-Usage: classify_subminer_diff.sh [path ...]
-
-Emit suggested verification lanes for explicit paths or current local git changes.
-
-Output format:
-  lane:<name>
-  flag:<name>
-  reason:<text>
-EOF
-}
-
-has_item() {
-  local needle=$1
-  shift || true
-  local item
-  for item in "$@"; do
-    if [[ "$item" == "$needle" ]]; then
-      return 0
-    fi
-  done
-  return 1
-}
-
-add_lane() {
-  local lane=$1
-  if ! has_item "$lane" "${LANES[@]:-}"; then
-    LANES+=("$lane")
-  fi
-}
-
-add_flag() {
-  local flag=$1
-  if ! has_item "$flag" "${FLAGS[@]:-}"; then
-    FLAGS+=("$flag")
-  fi
-}
-
-add_reason() {
-  REASONS+=("$1")
-}
-
-collect_git_paths() {
-  local top_level
-  if ! top_level=$(git rev-parse --show-toplevel 2>/dev/null); then
-    return 0
-  fi
-
-  (
-    cd "$top_level"
-    if git rev-parse --verify HEAD >/dev/null 2>&1; then
-      git diff --name-only --relative HEAD --
-      git diff --name-only --relative --cached --
-    else
-      git diff --name-only --relative --
-      git diff --name-only --relative --cached --
-    fi
-    git ls-files --others --exclude-standard
-  ) | awk 'NF' | sort -u
-}
-
-if [[ "${1:-}" == "--help" || "${1:-}" == "-h" ]]; then
-  usage
-  exit 0
-fi
-
-declare -a PATHS=()
-declare -a LANES=()
-declare -a FLAGS=()
-declare -a REASONS=()
-
-if [[ $# -gt 0 ]]; then
-  while [[ $# -gt 0 ]]; do
-    PATHS+=("$1")
-    shift
-  done
-else
-  while IFS= read -r line; do
-    [[ -n "$line" ]] && PATHS+=("$line")
-  done < <(collect_git_paths)
-fi
-
-if [[ ${#PATHS[@]} -eq 0 ]]; then
-  add_lane "core"
-  add_reason "no changed paths detected -> default to core"
-fi
-
-for path in "${PATHS[@]}"; do
-  specialized=0
-
-  case "$path" in
-    docs-site/*|docs/*|changes/*|README.md)
-      add_lane "docs"
-      add_reason "$path -> docs"
-      specialized=1
-      ;;
-  esac
-
-  case "$path" in
-    src/config/*|src/generate-config-example.ts|src/verify-config-example.ts|docs-site/public/config.example.jsonc|config.example.jsonc)
-      add_lane "config"
-      add_reason "$path -> config"
-      specialized=1
-      ;;
-  esac
-
-  case "$path" in
-    stats/*)
-      add_lane "stats"
-      add_reason "$path -> stats"
-      specialized=1
-      ;;
-  esac
-
-  case "$path" in
-    launcher/*|plugin/subminer/*|plugin/subminer.conf|scripts/test-plugin-*|scripts/get-mpv-window-*|scripts/configure-plugin-binary-path.mjs)
-      add_lane "launcher-plugin"
-      add_reason "$path -> launcher-plugin"
-      add_flag "real-runtime-candidate"
-      add_reason "$path -> real-runtime-candidate"
-      specialized=1
-      ;;
-  esac
-
-  case "$path" in
-    src/main.ts|src/main-entry.ts|src/preload.ts|src/main/*|src/core/services/mpv*|src/core/services/overlay*|src/renderer/*|src/window-trackers/*|scripts/prepare-build-assets.mjs)
-      add_lane "runtime-compat"
-      add_reason "$path -> runtime-compat"
-      add_flag "real-runtime-candidate"
-      add_reason "$path -> real-runtime-candidate"
-      specialized=1
-      ;;
-  esac
-
-  if [[ "$specialized" == "0" ]]; then
-    case "$path" in
-      src/*|package.json|tsconfig*.json|scripts/*|Makefile)
-        add_lane "core"
-        add_reason "$path -> core"
-        ;;
-    esac
-  fi
-
-  case "$path" in
-    package.json|src/main.ts|src/main-entry.ts|src/preload.ts)
-      add_flag "broad-impact"
-      add_reason "$path -> broad-impact"
-      ;;
-  esac
-done
-
-if [[ ${#LANES[@]} -eq 0 ]]; then
-  add_lane "core"
-  add_reason "no lane-specific matches -> default to core"
-fi
-
-for lane in "${LANES[@]}"; do
-  printf 'lane:%s\n' "$lane"
-done
-
-for flag in "${FLAGS[@]}"; do
-  printf 'flag:%s\n' "$flag"
-done
-
-for reason in "${REASONS[@]}"; do
-  printf 'reason:%s\n' "$reason"
-done

plugins/subminer-workflow/skills/subminer-change-verification/scripts/verify_subminer_change.sh

@@ -1,537 +0,0 @@
-#!/usr/bin/env bash
-set -euo pipefail
-
-usage() {
-  cat <<'EOF'
-Usage: verify_subminer_change.sh [options] [path ...]
-
-Options:
-  --lane <name>             Force a verification lane. Repeatable.
-  --artifact-dir <dir>      Use an explicit artifact directory.
-  --allow-real-runtime      Allow explicit real-runtime execution.
-  --allow-real-gui          Deprecated alias for --allow-real-runtime.
-  --dry-run                 Record planned steps without executing commands.
-  --help                    Show this help text.
-
-If no lanes are supplied, the script classifies the provided paths. If no paths are
-provided, it classifies the current local git changes.
-
-Authoritative real-runtime verification should be requested with explicit path
-arguments instead of relying on inferred local git changes.
-EOF
-}
-
-timestamp() {
-  date +%Y%m%d-%H%M%S
-}
-
-timestamp_iso() {
-  date -u +%Y-%m-%dT%H:%M:%SZ
-}
-
-generate_session_id() {
-  local tmp_dir
-  tmp_dir=$(mktemp -d "${TMPDIR:-/tmp}/subminer-verify-$(timestamp)-XXXXXX")
-  basename "$tmp_dir"
-  rmdir "$tmp_dir"
-}
-
-has_item() {
-  local needle=$1
-  shift || true
-  local item
-  for item in "$@"; do
-    if [[ "$item" == "$needle" ]]; then
-      return 0
-    fi
-  done
-  return 1
-}
-
-normalize_lane_name() {
-  case "$1" in
-    real-gui)
-      printf '%s' "real-runtime"
-      ;;
-    *)
-      printf '%s' "$1"
-      ;;
-  esac
-}
-
-add_lane() {
-  local lane
-  lane=$(normalize_lane_name "$1")
-  if ! has_item "$lane" "${SELECTED_LANES[@]:-}"; then
-    SELECTED_LANES+=("$lane")
-  fi
-}
-
-add_blocker() {
-  BLOCKERS+=("$1")
-  BLOCKED=1
-}
-
-validate_artifact_dir() {
-  local candidate=$1
-  if [[ ! "$candidate" =~ ^[A-Za-z0-9._/@:+-]+$ ]]; then
-    echo "Invalid characters in --artifact-dir path" >&2
-    exit 2
-  fi
-}
-
-append_step_record() {
-  printf '%s\t%s\t%s\t%s\t%s\t%s\t%s\t%s\n' \
-    "$1" "$2" "$3" "$4" "$5" "$6" "$7" "$8" >>"$STEPS_TSV"
-}
-
-record_env() {
-  {
-    printf 'repo_root=%s\n' "$REPO_ROOT"
-    printf 'session_id=%s\n' "$SESSION_ID"
-    printf 'artifact_dir=%s\n' "$ARTIFACT_DIR"
-    printf 'path_selection_mode=%s\n' "$PATH_SELECTION_MODE"
-    printf 'dry_run=%s\n' "$DRY_RUN"
-    printf 'allow_real_runtime=%s\n' "$ALLOW_REAL_RUNTIME"
-    printf 'session_home=%s\n' "$SESSION_HOME"
-    printf 'session_xdg_config_home=%s\n' "$SESSION_XDG_CONFIG_HOME"
-    printf 'session_mpv_dir=%s\n' "$SESSION_MPV_DIR"
-    printf 'session_logs_dir=%s\n' "$SESSION_LOGS_DIR"
-    printf 'session_mpv_log=%s\n' "$SESSION_MPV_LOG"
-    printf 'pwd=%s\n' "$(pwd)"
-    git rev-parse --short HEAD 2>/dev/null | sed 's/^/git_head=/' || true
-    git status --short 2>/dev/null || true
-    if [[ ${#PATH_ARGS[@]} -gt 0 ]]; then
-      printf 'requested_paths=\n'
-      printf '  %s\n' "${PATH_ARGS[@]}"
-    fi
-  } >"$ARTIFACT_DIR/env.txt"
-}
-
-run_step() {
-  local lane=$1
-  local name=$2
-  local command=$3
-  local note=${4:-}
-  local lane_slug=${lane//[^a-zA-Z0-9_-]/-}
-  local slug=${name//[^a-zA-Z0-9_-]/-}
-  local step_slug="${lane_slug}--${slug}"
-  local stdout_rel="steps/${step_slug}.stdout.log"
-  local stderr_rel="steps/${step_slug}.stderr.log"
-  local stdout_path="$ARTIFACT_DIR/$stdout_rel"
-  local stderr_path="$ARTIFACT_DIR/$stderr_rel"
-  local status exit_code
-
-  COMMANDS_RUN+=("$command")
-  printf '%s\n' "$command" >"$ARTIFACT_DIR/steps/${step_slug}.command.txt"
-
-  if [[ "$DRY_RUN" == "1" ]]; then
-    printf '[dry-run] %s\n' "$command" >"$stdout_path"
-    : >"$stderr_path"
-    status="dry-run"
-    exit_code=0
-  else
-    if HOME="$SESSION_HOME" \
-      XDG_CONFIG_HOME="$SESSION_XDG_CONFIG_HOME" \
-      SUBMINER_SESSION_LOGS_DIR="$SESSION_LOGS_DIR" \
-      SUBMINER_SESSION_MPV_LOG="$SESSION_MPV_LOG" \
-      bash -c "cd \"$REPO_ROOT\" && $command" >"$stdout_path" 2>"$stderr_path"; then
-      status="passed"
-      exit_code=0
-      EXECUTED_REAL_STEPS=1
-    else
-      exit_code=$?
-      status="failed"
-      FAILED=1
-    fi
-  fi
-
-  append_step_record "$lane" "$name" "$status" "$exit_code" "$command" "$stdout_rel" "$stderr_rel" "$note"
-  printf '%s\t%s\t%s\n' "$lane" "$name" "$status"
-
-  if [[ "$status" == "failed" ]]; then
-    FAILURE_STEP="$name"
-    FAILURE_COMMAND="$command"
-    FAILURE_STDOUT="$stdout_rel"
-    FAILURE_STDERR="$stderr_rel"
-    return "$exit_code"
-  fi
-}
-
-record_nonpassing_step() {
-  local lane=$1
-  local name=$2
-  local status=$3
-  local note=$4
-  local lane_slug=${lane//[^a-zA-Z0-9_-]/-}
-  local slug=${name//[^a-zA-Z0-9_-]/-}
-  local step_slug="${lane_slug}--${slug}"
-  local stdout_rel="steps/${step_slug}.stdout.log"
-  local stderr_rel="steps/${step_slug}.stderr.log"
-  printf '%s\n' "$note" >"$ARTIFACT_DIR/$stdout_rel"
-  : >"$ARTIFACT_DIR/$stderr_rel"
-  append_step_record "$lane" "$name" "$status" "0" "" "$stdout_rel" "$stderr_rel" "$note"
-  printf '%s\t%s\t%s\n' "$lane" "$name" "$status"
-}
-
-record_skipped_step() {
-  record_nonpassing_step "$1" "$2" "skipped" "$3"
-}
-
-record_blocked_step() {
-  add_blocker "$3"
-  record_nonpassing_step "$1" "$2" "blocked" "$3"
-}
-
-record_failed_step() {
-  FAILED=1
-  FAILURE_STEP=$2
-  FAILURE_COMMAND=${FAILURE_COMMAND:-"(validation)"}
-  local lane_slug=${1//[^a-zA-Z0-9_-]/-}
-  local step_slug=${2//[^a-zA-Z0-9_-]/-}
-  FAILURE_STDOUT="steps/${lane_slug}--${step_slug}.stdout.log"
-  FAILURE_STDERR="steps/${lane_slug}--${step_slug}.stderr.log"
-  add_blocker "$3"
-  record_nonpassing_step "$1" "$2" "failed" "$3"
-}
-
-find_real_runtime_helper() {
-  local candidate
-  for candidate in \
-    "$SCRIPT_DIR/run_real_runtime_smoke.sh" \
-    "$SCRIPT_DIR/run_real_mpv_smoke.sh"; do
-    if [[ -x "$candidate" ]]; then
-      printf '%s' "$candidate"
-      return 0
-    fi
-  done
-  return 1
-}
-
-acquire_real_runtime_lease() {
-  local lease_root="$REPO_ROOT/.tmp/skill-verification/locks"
-  local lease_dir="$lease_root/exclusive-real-runtime"
-  mkdir -p "$lease_root"
-  if mkdir "$lease_dir" 2>/dev/null; then
-    REAL_RUNTIME_LEASE_DIR="$lease_dir"
-    printf '%s\n' "$SESSION_ID" >"$lease_dir/session_id"
-    return 0
-  fi
-
-  local owner=""
-  if [[ -f "$lease_dir/session_id" ]]; then
-    owner=$(cat "$lease_dir/session_id")
-  fi
-  REAL_RUNTIME_LEASE_ERROR="real-runtime lease already held${owner:+ by $owner}"
-  return 1
-}
-
-release_real_runtime_lease() {
-  if [[ -n "$REAL_RUNTIME_LEASE_DIR" && -d "$REAL_RUNTIME_LEASE_DIR" ]]; then
-    if [[ -f "$REAL_RUNTIME_LEASE_DIR/session_id" ]]; then
-      local owner
-      owner=$(cat "$REAL_RUNTIME_LEASE_DIR/session_id")
-      if [[ "$owner" != "$SESSION_ID" ]]; then
-        return 0
-      fi
-    fi
-    rm -rf "$REAL_RUNTIME_LEASE_DIR"
-  fi
-}
-
-compute_final_status() {
-  if [[ "$FAILED" == "1" ]]; then
-    FINAL_STATUS="failed"
-  elif [[ "$BLOCKED" == "1" ]]; then
-    FINAL_STATUS="blocked"
-  elif [[ "$EXECUTED_REAL_STEPS" == "1" ]]; then
-    FINAL_STATUS="passed"
-  else
-    FINAL_STATUS="skipped"
-  fi
-}
-
-write_summary_files() {
-  local lane_lines
-  lane_lines=$(printf '%s\n' "${SELECTED_LANES[@]}")
-  printf '%s\n' "$lane_lines" >"$ARTIFACT_DIR/lanes.txt"
-  # bash 3.2 raises "unbound variable" under set -u when expanding an empty
-  # array, so guard on length (matching the idiom used elsewhere here).
-  if [[ ${#BLOCKERS[@]} -gt 0 ]]; then
-    printf '%s\n' "${BLOCKERS[@]}" >"$ARTIFACT_DIR/blockers.txt"
-  else
-    : >"$ARTIFACT_DIR/blockers.txt"
-  fi
-  if [[ ${#PATH_ARGS[@]} -gt 0 ]]; then
-    printf '%s\n' "${PATH_ARGS[@]}" >"$ARTIFACT_DIR/requested-paths.txt"
-  else
-    : >"$ARTIFACT_DIR/requested-paths.txt"
-  fi
-
-  ARTIFACT_DIR_ENV="$ARTIFACT_DIR" \
-  SESSION_ID_ENV="$SESSION_ID" \
-  FINAL_STATUS_ENV="$FINAL_STATUS" \
-  PATH_SELECTION_MODE_ENV="$PATH_SELECTION_MODE" \
-  ALLOW_REAL_RUNTIME_ENV="$ALLOW_REAL_RUNTIME" \
-  SESSION_HOME_ENV="$SESSION_HOME" \
-  SESSION_XDG_CONFIG_HOME_ENV="$SESSION_XDG_CONFIG_HOME" \
-  SESSION_MPV_DIR_ENV="$SESSION_MPV_DIR" \
-  SESSION_LOGS_DIR_ENV="$SESSION_LOGS_DIR" \
-  SESSION_MPV_LOG_ENV="$SESSION_MPV_LOG" \
-  STARTED_AT_ENV="$STARTED_AT" \
-  FINISHED_AT_ENV="$FINISHED_AT" \
-  FAILED_ENV="$FAILED" \
-  FAILURE_COMMAND_ENV="${FAILURE_COMMAND:-}" \
-  FAILURE_STDOUT_ENV="${FAILURE_STDOUT:-}" \
-  FAILURE_STDERR_ENV="${FAILURE_STDERR:-}" \
-  bun -e '
-    const fs = require("fs");
-    const path = require("path");
-
-    const lines = fs
-      .readFileSync(path.join(process.env.ARTIFACT_DIR_ENV, "steps.tsv"), "utf8")
-      .trim()
-      .split("\n")
-      .filter(Boolean)
-      .slice(1)
-      .map((line) => {
-        const [lane, name, status, exitCode, command, stdout, stderr, note] = line.split("\t");
-        return { lane, name, status, exitCode: Number(exitCode), command, stdout, stderr, note };
-      });
-
-    const payload = {
-      sessionId: process.env.SESSION_ID_ENV,
-      startedAt: process.env.STARTED_AT_ENV,
-      finishedAt: process.env.FINISHED_AT_ENV,
-      status: process.env.FINAL_STATUS_ENV,
-      pathSelectionMode: process.env.PATH_SELECTION_MODE_ENV,
-      allowRealRuntime: process.env.ALLOW_REAL_RUNTIME_ENV === "1",
-      sessionHome: process.env.SESSION_HOME_ENV,
-      sessionXdgConfigHome: process.env.SESSION_XDG_CONFIG_HOME_ENV,
-      sessionMpvDir: process.env.SESSION_MPV_DIR_ENV,
-      sessionLogsDir: process.env.SESSION_LOGS_DIR_ENV,
-      sessionMpvLog: process.env.SESSION_MPV_LOG_ENV,
-      failed: process.env.FAILED_ENV === "1",
-      failure: process.env.FAILURE_COMMAND_ENV
-        ? {
-            command: process.env.FAILURE_COMMAND_ENV,
-            stdout: process.env.FAILURE_STDOUT_ENV,
-            stderr: process.env.FAILURE_STDERR_ENV,
-          }
-        : null,
-      blockers: fs
-        .readFileSync(path.join(process.env.ARTIFACT_DIR_ENV, "blockers.txt"), "utf8")
-        .split("\n")
-        .filter(Boolean),
-      lanes: fs
-        .readFileSync(path.join(process.env.ARTIFACT_DIR_ENV, "lanes.txt"), "utf8")
-        .split("\n")
-        .filter(Boolean),
-      requestedPaths: fs
-        .readFileSync(path.join(process.env.ARTIFACT_DIR_ENV, "requested-paths.txt"), "utf8")
-        .split("\n")
-        .filter(Boolean),
-      steps: lines,
-    };
-
-    fs.writeFileSync(
-      path.join(process.env.ARTIFACT_DIR_ENV, "summary.json"),
-      JSON.stringify(payload, null, 2) + "\n",
-    );
-
-    const summaryLines = [
-      `status: ${payload.status}`,
-      `session: ${payload.sessionId}`,
-      `artifacts: ${process.env.ARTIFACT_DIR_ENV}`,
-      `lanes: ${payload.lanes.join(", ") || "(none)"}`,
-    ];
-
-    if (payload.requestedPaths.length > 0) {
-      summaryLines.push("requested paths:");
-      for (const entry of payload.requestedPaths) {
-        summaryLines.push(`- ${entry}`);
-      }
-    }
-
-    if (payload.failure) {
-      summaryLines.push(`failure command: ${payload.failure.command}`);
-      summaryLines.push(`failure stdout: ${payload.failure.stdout}`);
-      summaryLines.push(`failure stderr: ${payload.failure.stderr}`);
-    }
-
-    if (payload.blockers.length > 0) {
-      summaryLines.push("blockers:");
-      for (const blocker of payload.blockers) {
-        summaryLines.push(`- ${blocker}`);
-      }
-    }
-
-    summaryLines.push("steps:");
-    for (const step of payload.steps) {
-      summaryLines.push(`- ${step.lane}/${step.name}: ${step.status}`);
-    }
-
-    fs.writeFileSync(
-      path.join(process.env.ARTIFACT_DIR_ENV, "summary.txt"),
-      summaryLines.join("\n") + "\n",
-    );
-  '
-}
-
-SCRIPT_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
-SKILL_DIR=$(cd "$SCRIPT_DIR/.." && pwd)
-REPO_ROOT=$(git rev-parse --show-toplevel 2>/dev/null || pwd)
-
-declare -a PATH_ARGS=()
-declare -a SELECTED_LANES=()
-declare -a COMMANDS_RUN=()
-declare -a BLOCKERS=()
-
-ALLOW_REAL_RUNTIME=0
-DRY_RUN=0
-FAILED=0
-BLOCKED=0
-EXECUTED_REAL_STEPS=0
-FAILURE_STEP=""
-FAILURE_COMMAND=""
-FAILURE_STDOUT=""
-FAILURE_STDERR=""
-REAL_RUNTIME_LEASE_DIR=""
-REAL_RUNTIME_LEASE_ERROR=""
-PATH_SELECTION_MODE="auto"
-
-trap 'release_real_runtime_lease' EXIT
-
-while [[ $# -gt 0 ]]; do
-  case "$1" in
-    --lane)
-      shift
-      [[ $# -gt 0 ]] || {
-        echo "Missing value for --lane" >&2
-        exit 2
-      }
-      add_lane "$1"
-      PATH_SELECTION_MODE="explicit-lanes"
-      ;;
-    --artifact-dir)
-      shift
-      [[ $# -gt 0 ]] || {
-        echo "Missing value for --artifact-dir" >&2
-        exit 2
-      }
-      ARTIFACT_DIR=$1
-      ;;
-    --allow-real-runtime|--allow-real-gui)
-      ALLOW_REAL_RUNTIME=1
-      ;;
-    --dry-run)
-      DRY_RUN=1
-      ;;
-    --help|-h)
-      usage
-      exit 0
-      ;;
-    *)
-      PATH_ARGS+=("$1")
-      ;;
-  esac
-  shift || true
-done
-
-if [[ -z "${ARTIFACT_DIR:-}" ]]; then
-  SESSION_ID=$(generate_session_id)
-  ARTIFACT_DIR="$REPO_ROOT/.tmp/skill-verification/$SESSION_ID"
-else
-  validate_artifact_dir "$ARTIFACT_DIR"
-  SESSION_ID=$(basename "$ARTIFACT_DIR")
-fi
-
-mkdir -p "$ARTIFACT_DIR/steps"
-STEPS_TSV="$ARTIFACT_DIR/steps.tsv"
-printf 'lane\tstep\tstatus\texit_code\tcommand\tstdout\tstderr\tnote\n' >"$STEPS_TSV"
-
-STARTED_AT=$(timestamp_iso)
-SESSION_HOME="$REPO_ROOT/.tmp/skill-verification/runtime/$SESSION_ID/home"
-SESSION_XDG_CONFIG_HOME="$REPO_ROOT/.tmp/skill-verification/runtime/$SESSION_ID/xdg-config"
-SESSION_MPV_DIR="$SESSION_XDG_CONFIG_HOME/mpv"
-SESSION_LOGS_DIR="$REPO_ROOT/.tmp/skill-verification/runtime/$SESSION_ID/logs"
-SESSION_MPV_LOG="$SESSION_LOGS_DIR/mpv.log"
-mkdir -p "$SESSION_HOME" "$SESSION_MPV_DIR" "$SESSION_LOGS_DIR"
-
-CLASSIFIER_OUTPUT="$ARTIFACT_DIR/classification.txt"
-if [[ ${#SELECTED_LANES[@]} -eq 0 ]]; then
-  if [[ ${#PATH_ARGS[@]} -gt 0 ]]; then
-    PATH_SELECTION_MODE="explicit-paths"
-  fi
-  if "$SCRIPT_DIR/classify_subminer_diff.sh" "${PATH_ARGS[@]}" >"$CLASSIFIER_OUTPUT"; then
-    while IFS= read -r line; do
-      case "$line" in
-        lane:*)
-          add_lane "${line#lane:}"
-          ;;
-      esac
-    done <"$CLASSIFIER_OUTPUT"
-  else
-    record_failed_step "meta" "classify" "classification failed"
-  fi
-else
-  : >"$CLASSIFIER_OUTPUT"
-fi
-
-record_env
-
-if [[ ${#SELECTED_LANES[@]} -eq 0 ]]; then
-  add_lane "core"
-fi
-
-for lane in "${SELECTED_LANES[@]}"; do
-  case "$lane" in
-    docs)
-      run_step "$lane" "docs-kb" "bun run test:docs:kb" || break
-      ;;
-    config)
-      run_step "$lane" "config" "bun run test:config" || break
-      ;;
-    stats)
-      run_step "$lane" "stats" "bun run test:stats" || break
-      ;;
-    core)
-      run_step "$lane" "typecheck" "bun run typecheck" || break
-      run_step "$lane" "fast-tests" "bun run test:fast" || break
-      ;;
-    launcher-plugin)
-      run_step "$lane" "launcher" "bun run test:launcher" || break
-      run_step "$lane" "plugin-src" "bun run test:plugin:src" || break
-      ;;
-    runtime-compat)
-      run_step "$lane" "runtime-compat" "bun run test:runtime:compat" || break
-      ;;
-    real-runtime)
-      if [[ "$ALLOW_REAL_RUNTIME" != "1" ]]; then
-        record_blocked_step "$lane" "real-runtime" "real-runtime requested without --allow-real-runtime"
-        continue
-      fi
-      if ! acquire_real_runtime_lease; then
-        record_blocked_step "$lane" "real-runtime-lease" "$REAL_RUNTIME_LEASE_ERROR"
-        continue
-      fi
-      helper=$(find_real_runtime_helper || true)
-      if [[ -z "${helper:-}" ]]; then
-        record_blocked_step "$lane" "real-runtime-helper" "no real-runtime helper script available in $SCRIPT_DIR"
-        continue
-      fi
-      run_step "$lane" "real-runtime" "\"$helper\" \"$SESSION_ID\" \"$ARTIFACT_DIR\"" || break
-      ;;
-    *)
-      record_blocked_step "$lane" "unknown-lane" "unknown lane: $lane"
-      ;;
-  esac
-done
-
-release_real_runtime_lease
-FINISHED_AT=$(timestamp_iso)
-compute_final_status
-write_summary_files
-
-printf 'summary:%s\n' "$ARTIFACT_DIR/summary.txt"
-cat "$ARTIFACT_DIR/summary.txt"

plugins/subminer-workflow/skills/subminer-scrum-master/SKILL.md

@@ -1,118 +0,0 @@
----
-name: 'subminer-scrum-master'
-description: 'Use in the SubMiner repo when a request should be turned into planned work and driven through execution. Records a plan, dispatches one or more subagents when useful, and requires verification before handoff.'
----
-
-# SubMiner Scrum Master
-
-Canonical source: this plugin path.
-
-Own workflow, not code by default.
-
-Use this skill when the user gives a feature request, bug report, issue, refactor, or implementation ask and the agent should manage intake, planning, worker dispatch, and verification through completion.
-
-## Core Rules
-
-1. Keep the process light for questions, obvious mechanical edits, and tiny isolated changes.
-2. Record a plan before dispatching coding work.
-3. Split multi-part work into clear phases and ownership areas.
-4. Dispatch conservatively. Parallelize only disjoint write scopes.
-5. Require verification before handoff, typically via `subminer-change-verification`.
-6. Report dispatched workers, verification, blockers, and remaining risks.
-
-## Intake Workflow
-
-1. Parse the request.
-   Classify it as question, mechanical edit, bugfix, feature, refactor, investigation, or follow-up.
-2. Write a short working plan in-thread when the work is nontrivial.
-3. Choose execution mode:
-   - no subagents for trivial work
-   - one worker for focused work
-   - parallel workers only for disjoint scopes
-4. Run verification before handoff.
-
-## Dispatch Rules
-
-The scrum master orchestrates. Workers implement.
-
-- Do not become the default implementer unless delegation is unnecessary.
-- Do not parallelize overlapping files or tightly coupled runtime work.
-- Give every worker explicit ownership of files/modules.
-- Tell every worker other agents may be active and they must not revert unrelated edits.
-- Require each worker to report:
-  - changed files
-  - tests run
-  - blockers
-
-Use worker agents for implementation and explorer agents only for bounded codebase questions.
-
-## Verification
-
-Every nontrivial code task gets verification.
-
-Preferred flow:
-
-1. use `subminer-change-verification`
-2. start with the cheapest sufficient lane
-3. escalate only when needed
-4. if worker verification is sufficient, accept it or run one final consolidating pass
-
-Never hand off nontrivial work without stating what was verified and what was skipped.
-
-## Pre-Handoff Policy Checks
-
-Before handoff, always ask and answer both questions explicitly:
-
-1. Docs update required?
-2. Changelog fragment required?
-
-Rules:
-
-- Do not assume silence implies "no."
-- If the answer is yes, complete the update or report the blocker.
-- Include final yes/no answers in the handoff summary even when both answers are "no."
-
-## Failure / Scope Handling
-
-- If a worker hits ambiguity, pause and ask the user.
-- If verification fails, either:
-  - send the worker back with exact failure context, or
-  - fix it directly if it is tiny and clearly in scope
-- If new scope appears, pause and re-plan before silently expanding work.
-
-## Representative Flows
-
-### Trivial work
-
-- keep a short plan
-- implement directly or with one worker if helpful
-- run targeted verification
-- report outcome concisely
-
-### Focused implementation
-
-- record plan
-- dispatch one worker
-- integrate
-- verify
-- report outcome
-
-### Multi-part execution
-
-- define distinct deliverables/phases
-- record sequencing in the plan
-- dispatch workers only where scopes are disjoint
-- integrate
-- run consolidated verification
-- report outcome
-
-## Output Expectations
-
-At the end, report:
-
-- which workers were dispatched and what they owned
-- what verification ran
-- explicit answers to:
-  - docs update required?
-  - changelog fragment required?
-- blockers, skips, and risks

scripts/docs-knowledge-base.test.ts

@@ -19,6 +19,7 @@ const requiredDocs = [
   'docs/knowledge-base/catalog.md',
   'docs/knowledge-base/quality.md',
   'docs/workflow/README.md',
+  'docs/workflow/agent-skills.md',
   'docs/workflow/planning.md',
   'docs/workflow/verification.md',
 ] as const;

scripts/subminer-change-verification.test.ts

@@ -1,202 +0,0 @@
-import assert from 'node:assert/strict';
-import fs from 'node:fs';
-import os from 'node:os';
-import path from 'node:path';
-import { spawnSync } from 'node:child_process';
-import test from 'node:test';
-
-const repoRoot = process.cwd();
-const classifyScript = path.join(
-  repoRoot,
-  '.agents/skills/subminer-change-verification/scripts/classify_subminer_diff.sh',
-);
-const verifyScript = path.join(
-  repoRoot,
-  '.agents/skills/subminer-change-verification/scripts/verify_subminer_change.sh',
-);
-
-function withTempDir<T>(fn: (dir: string) => T): T {
-  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-change-verification-test-'));
-  try {
-    return fn(dir);
-  } finally {
-    fs.rmSync(dir, { recursive: true, force: true });
-  }
-}
-
-function runBash(args: string[]) {
-  return spawnSync('bash', args, {
-    cwd: repoRoot,
-    env: process.env,
-    encoding: 'utf8',
-  });
-}
-
-function parseArtifactDir(stdout: string): string {
-  const match = stdout.match(/^artifacts: (.+)$/m);
-  assert.ok(match, `expected artifact_dir in stdout, got:\n${stdout}`);
-  return match[1] ?? '';
-}
-
-function readSummaryJson(artifactDir: string) {
-  return JSON.parse(fs.readFileSync(path.join(artifactDir, 'summary.json'), 'utf8')) as {
-    sessionId: string;
-    status: string;
-    lanes: string[];
-    blockers?: string[];
-    artifactDir: string;
-    pathSelectionMode?: string;
-    steps: Array<{
-      lane: string;
-      name: string;
-      stdout: string;
-      stderr: string;
-      note: string;
-    }>;
-  };
-}
-
-test('classifier marks launcher and plugin paths as real-runtime candidates', () => {
-  const result = runBash([classifyScript, 'launcher/mpv.ts', 'plugin/subminer/process.lua']);
-
-  assert.equal(result.status, 0, result.stderr || result.stdout);
-  assert.match(result.stdout, /^lane:launcher-plugin$/m);
-  assert.match(result.stdout, /^flag:real-runtime-candidate$/m);
-  assert.doesNotMatch(result.stdout, /real-gui-candidate/);
-});
-
-test('verifier blocks requested real-runtime lane when runtime execution is not allowed', () => {
-  withTempDir((root) => {
-    const artifactDir = path.join(root, 'artifacts');
-    const result = runBash([
-      verifyScript,
-      '--dry-run',
-      '--artifact-dir',
-      artifactDir,
-      '--lane',
-      'real-runtime',
-      'launcher/mpv.ts',
-    ]);
-
-    assert.equal(result.status, 0, result.stdout);
-
-    const summary = readSummaryJson(artifactDir);
-    assert.equal(summary.status, 'blocked');
-    assert.deepEqual(summary.lanes, ['real-runtime']);
-    assert.ok(summary.sessionId.length > 0);
-    assert.ok(summary.blockers?.some((entry) => entry.includes('--allow-real-runtime')));
-    assert.equal(fs.existsSync(path.join(artifactDir, 'summary.json')), true);
-  });
-});
-
-test('verifier fails closed for unknown lanes', () => {
-  withTempDir((root) => {
-    const artifactDir = path.join(root, 'artifacts');
-    const result = runBash([
-      verifyScript,
-      '--dry-run',
-      '--artifact-dir',
-      artifactDir,
-      '--lane',
-      'not-a-lane',
-      'src/main.ts',
-    ]);
-
-    assert.equal(result.status, 0, result.stdout);
-
-    const summary = readSummaryJson(artifactDir);
-    assert.equal(summary.status, 'blocked');
-    assert.deepEqual(summary.lanes, ['not-a-lane']);
-    assert.ok(summary.blockers?.some((entry) => entry.includes('unknown lane')));
-  });
-});
-
-test('verifier keeps non-passing step artifacts distinct across lanes', () => {
-  withTempDir((root) => {
-    const artifactDir = path.join(root, 'artifacts');
-    const result = runBash([
-      verifyScript,
-      '--dry-run',
-      '--artifact-dir',
-      artifactDir,
-      '--lane',
-      'docs',
-      '--lane',
-      'not-a-lane',
-      'src/main.ts',
-    ]);
-
-    assert.equal(result.status, 0, result.stdout);
-
-    const summary = readSummaryJson(artifactDir);
-    const docsStep = summary.steps.find((step) => step.lane === 'docs' && step.name === 'docs-kb');
-    const unknownStep = summary.steps.find(
-      (step) => step.lane === 'not-a-lane' && step.name === 'unknown-lane',
-    );
-
-    assert.ok(docsStep);
-    assert.ok(unknownStep);
-    assert.notEqual(docsStep?.stdout, unknownStep?.stdout);
-    assert.equal(fs.existsSync(path.join(artifactDir, docsStep!.stdout)), true);
-    assert.equal(fs.existsSync(path.join(artifactDir, unknownStep!.stdout)), true);
-  });
-});
-
-test('verifier records the real-runtime lease blocker once', () => {
-  withTempDir((root) => {
-    const artifactDir = path.join(root, 'artifacts');
-    const leaseDir = path.join(
-      repoRoot,
-      '.tmp',
-      'skill-verification',
-      'locks',
-      'exclusive-real-runtime',
-    );
-    fs.mkdirSync(leaseDir, { recursive: true });
-    fs.writeFileSync(path.join(leaseDir, 'session_id'), 'other-session');
-
-    try {
-      const result = runBash([
-        verifyScript,
-        '--dry-run',
-        '--artifact-dir',
-        artifactDir,
-        '--allow-real-runtime',
-        '--lane',
-        'real-runtime',
-        'launcher/mpv.ts',
-      ]);
-
-      assert.equal(result.status, 0, result.stdout);
-
-      const summary = readSummaryJson(artifactDir);
-      assert.deepEqual(summary.blockers, ['real-runtime lease already held by other-session']);
-    } finally {
-      fs.rmSync(leaseDir, { recursive: true, force: true });
-    }
-  });
-});
-
-test('verifier allocates unique session ids and artifact roots by default', () => {
-  const first = runBash([verifyScript, '--dry-run', '--lane', 'core', 'src/main.ts']);
-  const second = runBash([verifyScript, '--dry-run', '--lane', 'core', 'src/main.ts']);
-
-  assert.equal(first.status, 0, first.stderr || first.stdout);
-  assert.equal(second.status, 0, second.stderr || second.stdout);
-
-  const firstArtifactDir = parseArtifactDir(first.stdout);
-  const secondArtifactDir = parseArtifactDir(second.stdout);
-
-  try {
-    const firstSummary = readSummaryJson(firstArtifactDir);
-    const secondSummary = readSummaryJson(secondArtifactDir);
-
-    assert.notEqual(firstSummary.sessionId, secondSummary.sessionId);
-    assert.notEqual(firstArtifactDir, secondArtifactDir);
-    assert.equal(firstSummary.pathSelectionMode, 'explicit-lanes');
-    assert.equal(secondSummary.pathSelectionMode, 'explicit-lanes');
-  } finally {
-    fs.rmSync(firstArtifactDir, { recursive: true, force: true });
-    fs.rmSync(secondArtifactDir, { recursive: true, force: true });
-  }
-});

src/cli/args.test.ts

@@ -399,6 +399,30 @@ test('hasExplicitCommand and shouldStartApp preserve command intent', () => {
   assert.equal(statsLifetimeRebuild.statsCleanupLifetime, true);
   assert.equal(statsLifetimeRebuild.statsCleanupVocab, false);
 
+  assert.throws(
+    () =>
+      parseArgs([
+        '--stats',
+        '--stats-cleanup',
+        '--stats-cleanup-duplicate-lines',
+        '--stats-cleanup-lookback-days',
+        '0.5',
+      ]),
+    /at least one day/,
+  );
+  assert.equal(
+    parseArgs([
+      '--stats',
+      '--stats-cleanup',
+      '--stats-cleanup-duplicate-lines',
+      '--stats-cleanup-lookback-days',
+      '1.5',
+    ]).statsCleanupLookbackDays,
+    1,
+  );
+  assert.equal(parseArgs(['--stats-cleanup-lookback-days=30']).statsCleanupLookbackDays, 30);
+  assert.throws(() => parseArgs(['--stats-cleanup-lookback-days=30=oops']), /at least one day/);
+
   const jellyfinLibraries = parseArgs(['--jellyfin-libraries']);
   assert.equal(jellyfinLibraries.jellyfinLibraries, true);
   assert.equal(hasExplicitCommand(jellyfinLibraries), true);

src/cli/args.ts

@@ -64,6 +64,9 @@ export interface CliArgs {
   statsCleanup?: boolean;
   statsCleanupVocab?: boolean;
   statsCleanupLifetime?: boolean;
+  statsCleanupDuplicateLines?: boolean;
+  statsCleanupDryRun?: boolean;
+  statsCleanupLookbackDays?: number;
   statsResponsePath?: string;
   jellyfin: boolean;
   jellyfinLogin: boolean;
@@ -109,6 +112,14 @@ export interface CliArgs {
 
 export type CliCommandSource = 'initial' | 'second-instance';
 
+function parseStatsCleanupLookbackDays(value: string | undefined): number {
+  const days = Number(value);
+  if (!Number.isFinite(days) || days < 1) {
+    throw new Error('Stats --lookback-days must be at least one day.');
+  }
+  return Math.floor(days);
+}
+
 export function parseArgs(argv: string[]): CliArgs {
   const args: CliArgs = {
     background: false,
@@ -167,6 +178,8 @@ export function parseArgs(argv: string[]): CliArgs {
     statsCleanup: false,
     statsCleanupVocab: false,
     statsCleanupLifetime: false,
+    statsCleanupDuplicateLines: false,
+    statsCleanupDryRun: false,
     jellyfin: false,
     jellyfinLogin: false,
     jellyfinLogout: false,
@@ -368,7 +381,15 @@ export function parseArgs(argv: string[]): CliArgs {
     } else if (arg === '--stats-cleanup') args.statsCleanup = true;
     else if (arg === '--stats-cleanup-vocab') args.statsCleanupVocab = true;
     else if (arg === '--stats-cleanup-lifetime') args.statsCleanupLifetime = true;
-    else if (arg.startsWith('--stats-response-path=')) {
+    else if (arg === '--stats-cleanup-duplicate-lines') args.statsCleanupDuplicateLines = true;
+    else if (arg === '--stats-cleanup-dry-run') args.statsCleanupDryRun = true;
+    else if (arg.startsWith('--stats-cleanup-lookback-days=')) {
+      args.statsCleanupLookbackDays = parseStatsCleanupLookbackDays(
+        arg.slice('--stats-cleanup-lookback-days='.length),
+      );
+    } else if (arg === '--stats-cleanup-lookback-days') {
+      args.statsCleanupLookbackDays = parseStatsCleanupLookbackDays(readValue(argv[i + 1]));
+    } else if (arg.startsWith('--stats-response-path=')) {
       const value = arg.split('=', 2)[1];
       if (value) args.statsResponsePath = value;
     } else if (arg === '--stats-response-path') {

src/core/services/__tests__/stats-server.test.ts

@@ -1032,6 +1032,180 @@ describe('stats server API routes', () => {
     ]);
   });
 
+  it('POST /api/stats/maintenance/duplicate-lines forwards the window and dry-run flag', async () => {
+    let seenOptions: unknown = null;
+    const summary = {
+      dryRun: true,
+      lookbackDays: 30,
+      scannedLines: 900,
+      burstGroups: 2,
+      removedLines: 180,
+      removedWordOccurrences: 540,
+      removedKanjiOccurrences: 120,
+      samples: [],
+    };
+    const app = createStatsApp(
+      createMockTracker({
+        cleanupDuplicateSubtitleLines: async (options: unknown) => {
+          seenOptions = options;
+          return summary;
+        },
+      }),
+    );
+
+    const res = await app.request('/api/stats/maintenance/duplicate-lines', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ dryRun: true, lookbackDays: 30 }),
+    });
+
+    assert.equal(res.status, 200);
+    assert.deepEqual(await res.json(), summary);
+    assert.deepEqual(seenOptions, { dryRun: true, lookbackDays: 30 });
+  });
+
+  it('POST /api/stats/maintenance/duplicate-lines rejects cross-origin simple requests', async () => {
+    let cleanupCalls = 0;
+    const app = createStatsApp(
+      createMockTracker({
+        cleanupDuplicateSubtitleLines: async () => {
+          cleanupCalls += 1;
+          throw new Error('cleanup must not run');
+        },
+      }),
+    );
+
+    const res = await app.request('/api/stats/maintenance/duplicate-lines', {
+      method: 'POST',
+      headers: {
+        'Content-Type': 'text/plain',
+        Origin: 'https://attacker.example',
+      },
+      body: JSON.stringify({ dryRun: false, lookbackDays: null }),
+    });
+
+    assert.equal(res.status, 415);
+    assert.equal(cleanupCalls, 0);
+  });
+
+  it('POST /api/stats/maintenance/duplicate-lines rejects a window shorter than a day', async () => {
+    let cleanupCalls = 0;
+    const app = createStatsApp(
+      createMockTracker({
+        cleanupDuplicateSubtitleLines: async () => {
+          cleanupCalls += 1;
+          return {
+            dryRun: true,
+            lookbackDays: null,
+            scannedLines: 0,
+            burstGroups: 0,
+            removedLines: 0,
+            removedWordOccurrences: 0,
+            removedKanjiOccurrences: 0,
+            samples: [],
+          };
+        },
+      }),
+    );
+
+    const res = await app.request('/api/stats/maintenance/duplicate-lines', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ dryRun: true, lookbackDays: 0.5 }),
+    });
+
+    assert.equal(res.status, 400);
+    assert.equal(cleanupCalls, 0);
+  });
+
+  it('POST /api/stats/maintenance/duplicate-lines floors a fractional multi-day window', async () => {
+    let seenOptions: unknown = null;
+    const app = createStatsApp(
+      createMockTracker({
+        cleanupDuplicateSubtitleLines: async (options: unknown) => {
+          seenOptions = options;
+          return {
+            dryRun: true,
+            lookbackDays: 1,
+            scannedLines: 0,
+            burstGroups: 0,
+            removedLines: 0,
+            removedWordOccurrences: 0,
+            removedKanjiOccurrences: 0,
+            samples: [],
+          };
+        },
+      }),
+    );
+
+    const res = await app.request('/api/stats/maintenance/duplicate-lines', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ dryRun: true, lookbackDays: 1.5 }),
+    });
+
+    assert.equal(res.status, 200);
+    assert.deepEqual(seenOptions, { dryRun: true, lookbackDays: 1 });
+  });
+
+  it('POST /api/stats/maintenance/duplicate-lines accepts an explicit empty object for all history', async () => {
+    let seenOptions: unknown = null;
+    const app = createStatsApp(
+      createMockTracker({
+        cleanupDuplicateSubtitleLines: async (options: unknown) => {
+          seenOptions = options;
+          return {
+            dryRun: false,
+            lookbackDays: null,
+            scannedLines: 0,
+            burstGroups: 0,
+            removedLines: 0,
+            removedWordOccurrences: 0,
+            removedKanjiOccurrences: 0,
+            samples: [],
+          };
+        },
+      }),
+    );
+
+    const res = await app.request('/api/stats/maintenance/duplicate-lines', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: '{}',
+    });
+
+    assert.equal(res.status, 200);
+    assert.deepEqual(seenOptions, { dryRun: false, lookbackDays: null });
+  });
+
+  for (const malformed of [
+    { name: 'a missing body', body: undefined },
+    { name: 'malformed JSON', body: '{' },
+    { name: 'JSON null', body: 'null' },
+    { name: 'a JSON array', body: '[]' },
+  ]) {
+    it(`POST /api/stats/maintenance/duplicate-lines rejects ${malformed.name}`, async () => {
+      let cleanupCalls = 0;
+      const app = createStatsApp(
+        createMockTracker({
+          cleanupDuplicateSubtitleLines: async () => {
+            cleanupCalls += 1;
+            throw new Error('cleanup must not run');
+          },
+        }),
+      );
+
+      const res = await app.request('/api/stats/maintenance/duplicate-lines', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: malformed.body,
+      });
+
+      assert.equal(res.status, 400);
+      assert.equal(cleanupCalls, 0);
+    });
+  }
+
   it('PUT /api/stats/excluded-words rejects malformed rows', async () => {
     const app = createStatsApp(createMockTracker());
 

src/core/services/immersion-tracker-service.ts

@@ -92,6 +92,11 @@ import {
   type RunDeleteMaintenanceTask,
 } from './immersion-tracker/delete-maintenance-worker-runtime';
 import { DeleteMaintenanceScheduler } from './immersion-tracker/delete-maintenance-scheduler';
+import {
+  cleanupDuplicateSubtitleLines,
+  type DuplicateSubtitleLineCleanupOptions,
+  type DuplicateSubtitleLineCleanupSummary,
+} from './immersion-tracker/duplicate-line-cleanup';
 import { repairJellyfinStreamVideoLinks } from './immersion-tracker/jellyfin-link-repair';
 import {
   repairLegacySeasonlessAnimeRows,
@@ -630,6 +635,18 @@ export class ImmersionTrackerService {
     });
   }
 
+  /**
+   * Collapse animation bursts that earlier versions recorded frame by frame. The whole
+   * queue is drained first so a burst still waiting to be written is scanned as stored
+   * rows rather than surviving the cleanup and landing a moment after it.
+   */
+  async cleanupDuplicateSubtitleLines(
+    options: DuplicateSubtitleLineCleanupOptions = {},
+  ): Promise<DuplicateSubtitleLineCleanupSummary> {
+    this.drainQueue();
+    return cleanupDuplicateSubtitleLines(this.db, options);
+  }
+
   async rebuildLifetimeSummaries(): Promise<LifetimeRebuildSummary> {
     this.flushTelemetry(true);
     this.flushNow();
@@ -1849,6 +1866,24 @@ export class ImmersionTrackerService {
     }
   }
 
+  /**
+   * Write out everything queued, not just the next batch.
+   *
+   * `flushNow` writes at most `batchSize` entries and does nothing at all while the write
+   * lock is held, so a maintenance pass that runs straight after it can still be reading
+   * a database that is missing rows. Each pass has to shrink the queue to continue: a
+   * failed flush puts its batch back, and looping on that would never finish.
+   */
+  private drainQueue(): void {
+    while (this.queue.length > 0) {
+      const pendingBefore = this.queue.length;
+      this.flushNow();
+      if (this.queue.length >= pendingBefore) {
+        return;
+      }
+    }
+  }
+
   private flushSingle(write: QueuedWrite): void {
     executeQueuedWrite(write, this.preparedStatements);
   }

src/core/services/immersion-tracker/__tests__/duplicate-line-cleanup.test.ts

@@ -0,0 +1,467 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+import { Database } from '../sqlite.js';
+import type { DatabaseSync } from '../sqlite.js';
+import { ensureSchema } from '../storage.js';
+import { cleanupDuplicateSubtitleLines } from '../duplicate-line-cleanup.js';
+
+const DAY_MS = 86_400_000;
+const BASE_MS = 1_700_000_000_000;
+const WORD_ID = 1;
+
+interface SeedLine {
+  session: number;
+  text: string;
+  startMs: number;
+  endMs: number;
+  /** Recording wall-clock, i.e. what the lookback window filters on. */
+  createdMs?: number;
+}
+
+function makeDbPath(): string {
+  const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-duplicate-line-test-'));
+  return path.join(dir, 'immersion.sqlite');
+}
+
+function cleanupDbPath(dbPath: string): void {
+  const dir = path.dirname(dbPath);
+  if (!fs.existsSync(dir)) return;
+  fs.rmSync(dir, { recursive: true, force: true });
+}
+
+/** One episode, two sessions of it, and one word occurrence per seeded line. */
+function seed(db: DatabaseSync, lines: SeedLine[]): void {
+  db.exec(`
+    INSERT INTO imm_anime(anime_id, normalized_title_key, canonical_title, CREATED_DATE, LAST_UPDATE_DATE)
+      VALUES (1, 'show', 'Show', ${BASE_MS}, ${BASE_MS});
+    INSERT INTO imm_videos(video_id, video_key, anime_id, canonical_title, source_type, watched, duration_ms, CREATED_DATE, LAST_UPDATE_DATE)
+      VALUES (1, 'v1', 1, 'Ep 1', 1, 1, 1440000, ${BASE_MS}, ${BASE_MS});
+    INSERT INTO imm_sessions(session_id, session_uuid, video_id, started_at_ms, ended_at_ms, status, CREATED_DATE, LAST_UPDATE_DATE)
+      VALUES (1, 's1', 1, '${BASE_MS}', '${BASE_MS + 1000}', 2, ${BASE_MS}, ${BASE_MS}),
+             (2, 's2', 1, '${BASE_MS + DAY_MS}', '${BASE_MS + DAY_MS + 1000}', 2, ${BASE_MS}, ${BASE_MS});
+    INSERT INTO imm_words(id, headword, word, reading, part_of_speech, pos1, first_seen, last_seen, frequency)
+      VALUES (${WORD_ID}, '飛び上がる', '飛び上がる', '', 'verb', '動詞', ${Math.floor(BASE_MS / 1000)}, ${Math.floor(BASE_MS / 1000)}, 0);
+  `);
+
+  const insertLine = db.prepare(
+    `INSERT INTO imm_subtitle_lines(
+       line_id, session_id, video_id, anime_id, line_index,
+       segment_start_ms, segment_end_ms, text, CREATED_DATE, LAST_UPDATE_DATE)
+     VALUES (?, ?, 1, 1, ?, ?, ?, ?, ?, ?)`,
+  );
+  const insertOccurrence = db.prepare(
+    `INSERT INTO imm_word_line_occurrences(line_id, word_id, occurrence_count, seen_ms)
+     VALUES (?, ?, 1, ?)`,
+  );
+
+  lines.forEach((line, index) => {
+    const lineId = index + 1;
+    const lineIndex = index + 1;
+    const createdMs = line.createdMs ?? BASE_MS;
+    insertLine.run(
+      lineId,
+      line.session,
+      lineIndex,
+      line.startMs,
+      line.endMs,
+      line.text,
+      createdMs,
+      createdMs,
+    );
+    insertOccurrence.run(lineId, WORD_ID, createdMs);
+  });
+
+  db.exec(`
+    UPDATE imm_words SET frequency = (
+      SELECT COALESCE(SUM(o.occurrence_count), 0)
+      FROM imm_word_line_occurrences o WHERE o.word_id = imm_words.id
+    )
+  `);
+}
+
+function createDb(lines: SeedLine[]): { db: DatabaseSync; dbPath: string } {
+  const dbPath = makeDbPath();
+  const db = new Database(dbPath);
+  ensureSchema(db);
+  seed(db, lines);
+  return { db, dbPath };
+}
+
+/** A typeset line mpv reported once per animation frame. */
+function karaokeFrames(
+  session: number,
+  text: string,
+  startMs: number,
+  frames: number,
+  frameMs: number,
+): SeedLine[] {
+  return Array.from({ length: frames }, (_, index) => ({
+    session,
+    text,
+    startMs: startMs + index * frameMs,
+    endMs: startMs + (index + 1) * frameMs,
+  }));
+}
+
+function countLines(db: DatabaseSync): number {
+  return (db.prepare('SELECT COUNT(*) AS total FROM imm_subtitle_lines').get() as { total: number })
+    .total;
+}
+
+function wordFrequency(db: DatabaseSync): number {
+  const row = db.prepare('SELECT frequency FROM imm_words WHERE id = ?').get(WORD_ID) as {
+    frequency: number;
+  } | null;
+  return row?.frequency ?? 0;
+}
+
+test('a karaoke burst collapses to one line and gives back its word counts', () => {
+  const { db, dbPath } = createDb([
+    ...karaokeFrames(1, '飛び上がる', 10_000, 40, 40),
+    { session: 1, text: 'おはよう', startMs: 20_000, endMs: 22_000 },
+  ]);
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 1);
+    assert.equal(summary.removedLines, 39);
+    assert.equal(summary.removedWordOccurrences, 39);
+    assert.equal(countLines(db), 2);
+    assert.equal(wordFrequency(db), 2);
+
+    // The surviving line covers the whole run, the way the parsed cue would.
+    const kept = db
+      .prepare(
+        'SELECT segment_start_ms AS startMs, segment_end_ms AS endMs FROM imm_subtitle_lines WHERE line_id = 1',
+      )
+      .get() as { startMs: number; endMs: number };
+    assert.equal(kept.startMs, 10_000);
+    assert.equal(kept.endMs, 10_000 + 40 * 40);
+
+    assert.equal(summary.samples.length, 1);
+    assert.equal(summary.samples[0]!.text, '飛び上がる');
+    assert.equal(summary.samples[0]!.frames, 40);
+    assert.equal(summary.samples[0]!.videoTitle, 'Ep 1');
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('ordinary repeated dialogue survives', () => {
+  // Six contiguous `飛び上がる`, each held for a normal beat rather than a frame.
+  const lines = Array.from({ length: 6 }, (_, index) => ({
+    session: 1,
+    text: '飛び上がる',
+    startMs: 5_000 + index * 800,
+    endMs: 5_000 + (index + 1) * 800,
+  }));
+  const { db, dbPath } = createDb(lines);
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 0);
+    assert.equal(summary.removedLines, 0);
+    assert.equal(countLines(db), 6);
+    assert.equal(wordFrequency(db), 6);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('a long run of quarter-second frames is still a burst', () => {
+  // Between the timing-only bound (0.1s) and the animation-frame bound (0.3s): heavier
+  // typesetting lands here, and the run length is what makes it conclusive.
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 10_000, 6, 250));
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 1);
+    assert.equal(summary.removedLines, 5);
+    assert.equal(countLines(db), 1);
+    assert.equal(wordFrequency(db), 1);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('a qualifying short-frame burst may end with one long hold frame', () => {
+  const { db, dbPath } = createDb([
+    ...karaokeFrames(1, '飛び上がる', 10_000, 8, 40),
+    { session: 1, text: '飛び上がる', startMs: 10_320, endMs: 12_320 },
+  ]);
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 1);
+    assert.equal(summary.removedLines, 8);
+    assert.equal(countLines(db), 1);
+    assert.equal(wordFrequency(db), 1);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('a long event before the final frame prevents burst cleanup', () => {
+  const { db, dbPath } = createDb([
+    ...karaokeFrames(1, '飛び上がる', 10_000, 5, 40),
+    { session: 1, text: '飛び上がる', startMs: 10_200, endMs: 12_200 },
+    { session: 1, text: '飛び上がる', startMs: 12_200, endMs: 12_240 },
+  ]);
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 0);
+    assert.equal(countLines(db), 7);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('a run of frames longer than the animation bound survives', () => {
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 10_000, 6, 400));
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 0);
+    assert.equal(countLines(db), 6);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('the four-frame residue the live gate stores is cleaned up', () => {
+  // The streaming gate records the first four frames of a burst before the run is long
+  // enough to recognise. Four contiguous identical events under the strict timing-only
+  // bound are that residue, and no real dialogue.
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 1_000, 4, 40));
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 1);
+    assert.equal(summary.removedLines, 3);
+    assert.equal(countLines(db), 1);
+    assert.equal(wordFrequency(db), 1);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('a four-frame run above the strict frame bound survives', () => {
+  // Long enough per event to be plausible dialogue; only a five-event run may use the
+  // looser animation-frame bound.
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 1_000, 4, 250));
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 0);
+    assert.equal(countLines(db), 4);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('an explicit minRunLength raises the bar', () => {
+  // Five quarter-second frames qualify under the defaults; a cautious run asking for six
+  // leaves them alone. Above the strict bound, so the residue rule stays out of it.
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 10_000, 5, 250));
+
+  try {
+    const preview = cleanupDuplicateSubtitleLines(db, { dryRun: true });
+    assert.equal(preview.burstGroups, 1);
+
+    const summary = cleanupDuplicateSubtitleLines(db, { minRunLength: 6 });
+    assert.equal(summary.burstGroups, 0);
+    assert.equal(countLines(db), 5);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('an explicit maxFrameSeconds tightens the frame bound', () => {
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 10_000, 6, 250));
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db, { maxFrameSeconds: 0.2 });
+
+    assert.equal(summary.burstGroups, 0);
+    assert.equal(countLines(db), 6);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('a non-finite maxFrameSeconds falls back to the default bound', () => {
+  // Six normal-beat lines: Infinity must not turn every event into a "short frame".
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 10_000, 6, 800));
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db, { maxFrameSeconds: Infinity });
+
+    assert.equal(summary.burstGroups, 0);
+    assert.equal(countLines(db), 6);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('sampleLimit zero removes bursts but reports no samples', () => {
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 10_000, 40, 40));
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db, { sampleLimit: 0 });
+
+    assert.equal(summary.removedLines, 39);
+    assert.deepEqual(summary.samples, []);
+    assert.equal(countLines(db), 1);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('a short run below every threshold survives', () => {
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 1_000, 3, 40));
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 0);
+    assert.equal(countLines(db), 3);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('interleaved dual-line karaoke collapses each line to one row', () => {
+  // Kanji and romaji lines frame-flipped together, the way fansub OPs are typeset. The
+  // rows arrive interleaved in time order; each text must still chain into its own run.
+  const kanji = karaokeFrames(1, '飛び上がる', 10_000, 20, 60);
+  const romaji = karaokeFrames(1, 'tobiagaru', 10_001, 20, 60);
+  const interleaved = [...kanji, ...romaji].sort((a, b) => a.startMs - b.startMs);
+  const { db, dbPath } = createDb(interleaved);
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 2);
+    assert.equal(summary.removedLines, 38);
+    assert.equal(countLines(db), 2);
+    assert.equal(wordFrequency(db), 2);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('the same line in a rewatch session is never merged into the first watch', () => {
+  const { db, dbPath } = createDb([
+    ...karaokeFrames(1, '飛び上がる', 10_000, 6, 40),
+    ...karaokeFrames(2, '飛び上がる', 10_000, 6, 40),
+  ]);
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 2);
+    assert.equal(summary.removedLines, 10);
+    // One surviving line per session, not one across both.
+    assert.equal(countLines(db), 2);
+    assert.equal(wordFrequency(db), 2);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('a gap between runs splits them', () => {
+  const { db, dbPath } = createDb([
+    ...karaokeFrames(1, '飛び上がる', 10_000, 6, 40),
+    ...karaokeFrames(1, '飛び上がる', 60_000, 6, 40),
+  ]);
+
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db);
+
+    assert.equal(summary.burstGroups, 2);
+    assert.equal(countLines(db), 2);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('a dry run reports what an apply would do and writes nothing', () => {
+  const { db, dbPath } = createDb(karaokeFrames(1, '飛び上がる', 10_000, 40, 40));
+
+  try {
+    const preview = cleanupDuplicateSubtitleLines(db, { dryRun: true });
+
+    assert.equal(preview.dryRun, true);
+    assert.equal(preview.removedLines, 39);
+    assert.equal(countLines(db), 40);
+    assert.equal(wordFrequency(db), 40);
+
+    const applied = cleanupDuplicateSubtitleLines(db);
+    assert.equal(applied.removedLines, preview.removedLines);
+    assert.equal(applied.removedWordOccurrences, preview.removedWordOccurrences);
+    assert.equal(countLines(db), 1);
+  } finally {
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});
+
+test('the lookback window leaves older bursts alone', () => {
+  const recentMs = BASE_MS;
+  const oldMs = BASE_MS - 40 * DAY_MS;
+  const { db, dbPath } = createDb([
+    ...karaokeFrames(1, '飛び上がる', 10_000, 6, 40).map((line) => ({
+      ...line,
+      createdMs: oldMs,
+    })),
+    ...karaokeFrames(2, '飛び上がる', 10_000, 6, 40).map((line) => ({
+      ...line,
+      createdMs: recentMs,
+    })),
+  ]);
+
+  globalThis.__subminerTestNowMs = BASE_MS;
+  try {
+    const summary = cleanupDuplicateSubtitleLines(db, { lookbackDays: 30 });
+
+    assert.equal(summary.lookbackDays, 30);
+    assert.equal(summary.scannedLines, 6);
+    assert.equal(summary.burstGroups, 1);
+    assert.equal(summary.removedLines, 5);
+    // Six untouched old frames plus the one surviving recent line.
+    assert.equal(countLines(db), 7);
+    assert.equal(wordFrequency(db), 7);
+  } finally {
+    globalThis.__subminerTestNowMs = undefined;
+    db.close();
+    cleanupDbPath(dbPath);
+  }
+});

src/core/services/immersion-tracker/duplicate-line-cleanup.ts

@@ -0,0 +1,423 @@
+/*
+ * Retroactive removal of animation-burst subtitle lines from the stats database.
+ *
+ * Before the live ingest gate existed, a karaoke OP recorded one line -- and one count
+ * for every word in it -- per animation frame, which is enough to put an OP lyric at the
+ * top of "Top Repeated Words" for good. This module finds those runs in what is already
+ * stored and takes them back down to one line.
+ *
+ * Only timing is available here: the stored text has been stripped of ASS markup, so the
+ * authoring evidence the file-level parser uses (`\t`, `\move`, karaoke timing, a
+ * changing override signature) is long gone. What is left is a run of identical,
+ * contiguous, short-lived lines inside a single session.
+ *
+ * The run has to be as long as the timing-only rule in `subtitle-cue-dedup` demands, but
+ * its short frames may be as long as the animation-frame bound rather than the much
+ * tighter timing-only one. A qualifying run may end with one longer hold, which is a
+ * common karaoke shape. Five or more repeats of the same text, each ending where the next
+ * begins, is already conclusive on its own -- no dialogue does that -- and the tighter
+ * bound would walk straight past the heavier typesetting that motivated this, where
+ * frames sit nearer a quarter of a second. Both bounds are options, so a cautious run can
+ * ask for more, and a dry run always reports before anything is removed.
+ *
+ * Scope: subtitle lines, their word/kanji occurrences, and the `imm_words`/`imm_kanji`
+ * aggregates those occurrences feed. Session telemetry (`lines_seen`, `tokens_seen`) and
+ * the rollups derived from it are left alone; they are cumulative samples taken at record
+ * time, and for sessions whose raw rows have since been pruned they cannot be recomputed.
+ */
+
+import type { DatabaseSync } from './sqlite';
+import {
+  ANIMATION_FRAME_MAX_SECONDS,
+  DUPLICATE_CUE_GAP_TOLERANCE_SECONDS,
+  MIN_STREAM_RESIDUE_FRAMES,
+  MIN_TIMING_ONLY_FRAMES,
+  TIMING_ONLY_FRAME_MAX_SECONDS,
+} from '../subtitle-burst-constants';
+import {
+  applyLexicalRemovals,
+  makePlaceholders,
+  planLexicalRemovalsForLines,
+  toDbTimestamp,
+} from './query-shared';
+import { nowMs } from './time';
+
+const MS_PER_DAY = 86_400_000;
+/** SQLite caps bound parameters per statement; stay well under it. */
+const ID_BATCH_SIZE = 400;
+const DEFAULT_SAMPLE_LIMIT = 20;
+
+export interface DuplicateSubtitleLineCleanupOptions {
+  /** Only consider lines recorded within this many days. Null or omitted = all history. */
+  lookbackDays?: number | null;
+  /** Measure without writing. */
+  dryRun?: boolean;
+  /** Identical contiguous lines needed before a run counts as an animation. */
+  minRunLength?: number;
+  /** Longest a single event may last and still look like an animation frame. */
+  maxFrameSeconds?: number;
+  /** How many of the largest runs to describe in the summary. */
+  sampleLimit?: number;
+}
+
+export interface DuplicateSubtitleLineBurst {
+  sessionId: number;
+  videoId: number;
+  text: string;
+  /** Kept line, extended to cover the whole run. */
+  keptLineId: number;
+  removedLineIds: number[];
+  startMs: number;
+  endMs: number;
+}
+
+export interface DuplicateSubtitleLineSample {
+  videoId: number;
+  videoTitle: string | null;
+  text: string;
+  frames: number;
+  removedLines: number;
+  startMs: number;
+  endMs: number;
+}
+
+export interface DuplicateSubtitleLineCleanupSummary {
+  dryRun: boolean;
+  lookbackDays: number | null;
+  scannedLines: number;
+  burstGroups: number;
+  removedLines: number;
+  removedWordOccurrences: number;
+  removedKanjiOccurrences: number;
+  samples: DuplicateSubtitleLineSample[];
+}
+
+export interface StoredSubtitleLineRow {
+  lineId: number;
+  sessionId: number;
+  videoId: number;
+  text: string;
+  startMs: number;
+  endMs: number;
+}
+
+interface ResolvedBounds {
+  lookbackDays: number | null;
+  minRunLength: number;
+  maxFrameMs: number;
+  /** Shorter runs qualify only when every event sits under this much stricter bound. */
+  residueMinRunLength: number;
+  strictFrameMs: number;
+  gapToleranceMs: number;
+  sampleLimit: number;
+}
+
+function resolveBounds(options: DuplicateSubtitleLineCleanupOptions): ResolvedBounds {
+  const lookbackDays =
+    typeof options.lookbackDays === 'number' && Number.isFinite(options.lookbackDays)
+      ? Math.max(1, Math.floor(options.lookbackDays))
+      : null;
+  const minRunLength =
+    typeof options.minRunLength === 'number' && Number.isFinite(options.minRunLength)
+      ? Math.max(2, Math.floor(options.minRunLength))
+      : MIN_TIMING_ONLY_FRAMES;
+  const maxFrameSeconds =
+    typeof options.maxFrameSeconds === 'number' &&
+    Number.isFinite(options.maxFrameSeconds) &&
+    options.maxFrameSeconds > 0
+      ? options.maxFrameSeconds
+      : ANIMATION_FRAME_MAX_SECONDS;
+  const sampleLimit =
+    typeof options.sampleLimit === 'number' && options.sampleLimit >= 0
+      ? Math.floor(options.sampleLimit)
+      : DEFAULT_SAMPLE_LIMIT;
+  return {
+    lookbackDays,
+    minRunLength,
+    maxFrameMs: Math.round(maxFrameSeconds * 1000),
+    residueMinRunLength: Math.max(MIN_STREAM_RESIDUE_FRAMES, minRunLength - 1),
+    strictFrameMs: Math.round(TIMING_ONLY_FRAME_MAX_SECONDS * 1000),
+    gapToleranceMs: Math.round(DUPLICATE_CUE_GAP_TOLERANCE_SECONDS * 1000),
+    sampleLimit,
+  };
+}
+
+/**
+ * `CREATED_DATE` holds epoch milliseconds on rows this app wrote, but older and synced
+ * rows can carry seconds, so normalize before comparing against the cutoff.
+ */
+const CREATED_MS_SQL = `
+  CASE
+    WHEN sl.CREATED_DATE < 10000000000 THEN sl.CREATED_DATE * 1000
+    ELSE sl.CREATED_DATE
+  END`;
+
+function readCandidateLines(db: DatabaseSync, bounds: ResolvedBounds): StoredSubtitleLineRow[] {
+  const scope =
+    bounds.lookbackDays === null
+      ? ''
+      : `AND sl.CREATED_DATE IS NOT NULL AND ${CREATED_MS_SQL} >= ?`;
+  const params = bounds.lookbackDays === null ? [] : [nowMs() - bounds.lookbackDays * MS_PER_DAY];
+  return db
+    .prepare(
+      `SELECT
+         sl.line_id AS lineId,
+         sl.session_id AS sessionId,
+         sl.video_id AS videoId,
+         sl.text AS text,
+         sl.segment_start_ms AS startMs,
+         sl.segment_end_ms AS endMs
+       FROM imm_subtitle_lines sl
+       WHERE sl.segment_start_ms IS NOT NULL
+         AND sl.segment_end_ms IS NOT NULL
+         ${scope}
+       ORDER BY sl.session_id, sl.video_id, sl.segment_start_ms, sl.line_id`,
+    )
+    .all(...params) as StoredSubtitleLineRow[];
+}
+
+function isBurst(run: StoredSubtitleLineRow[], bounds: ResolvedBounds): boolean {
+  const isShortFrame = (row: StoredSubtitleLineRow): boolean =>
+    row.endMs - row.startMs <= bounds.maxFrameMs;
+  // The residue the live gate leaves behind: it records the first frames of a burst
+  // before the run is long enough to recognise, so one frame fewer than the timing-only
+  // minimum, every one under the strict timing-only bound. No dialogue holds identical
+  // sub-tenth-second lines back to back that many times.
+  if (
+    run.length >= bounds.residueMinRunLength &&
+    run.every((row) => row.endMs - row.startMs <= bounds.strictFrameMs)
+  ) {
+    return true;
+  }
+  if (run.length < bounds.minRunLength) {
+    return false;
+  }
+  if (run.every(isShortFrame)) {
+    return true;
+  }
+  // Karaoke commonly finishes its short animation frames with one long hold. Only the
+  // final event may exceed the frame bound, and the short frames before it must already
+  // meet the minimum run length on their own.
+  return (
+    run.length - 1 >= bounds.minRunLength &&
+    run.slice(0, -1).every(isShortFrame) &&
+    !isShortFrame(run[run.length - 1]!)
+  );
+}
+
+function toBurst(run: StoredSubtitleLineRow[]): DuplicateSubtitleLineBurst {
+  const [first] = run;
+  return {
+    sessionId: first!.sessionId,
+    videoId: first!.videoId,
+    text: first!.text,
+    keptLineId: first!.lineId,
+    removedLineIds: run.slice(1).map((row) => row.lineId),
+    startMs: first!.startMs,
+    endMs: run.reduce((latest, row) => Math.max(latest, row.endMs), first!.endMs),
+  };
+}
+
+/**
+ * Group stored lines into animation runs.
+ *
+ * Rows are bucketed per (session, video, text) before chaining, the way the file-level
+ * dedup buckets cues: dual-line karaoke interleaves two texts frame by frame, and
+ * chaining across the interleave would break every run at length one.
+ *
+ * Runs never cross a session, which is what keeps a rewatch intact: the same episode
+ * watched twice stores the same line twice, and those two belong to different sessions.
+ */
+export function findDuplicateSubtitleLineBursts(
+  rows: readonly StoredSubtitleLineRow[],
+  options: DuplicateSubtitleLineCleanupOptions = {},
+): DuplicateSubtitleLineBurst[] {
+  const bounds = resolveBounds(options);
+
+  // Insertion order preserves the query's startMs ordering within each bucket.
+  const rowsByKey = new Map<string, StoredSubtitleLineRow[]>();
+  for (const row of rows) {
+    const key = `${row.sessionId}|${row.videoId}|${row.text}`;
+    const bucket = rowsByKey.get(key);
+    if (bucket) {
+      bucket.push(row);
+    } else {
+      rowsByKey.set(key, [row]);
+    }
+  }
+
+  const bursts: DuplicateSubtitleLineBurst[] = [];
+  for (const bucket of rowsByKey.values()) {
+    if (bucket.length < 2) {
+      continue;
+    }
+
+    let run: StoredSubtitleLineRow[] = [];
+    let chainEndMs = 0;
+
+    const closeRun = (): void => {
+      if (run.length > 1 && isBurst(run, bounds)) {
+        bursts.push(toBurst(run));
+      }
+      run = [];
+    };
+
+    for (const row of bucket) {
+      if (run.length > 0 && row.startMs <= chainEndMs + bounds.gapToleranceMs) {
+        run.push(row);
+        chainEndMs = Math.max(chainEndMs, row.endMs);
+        continue;
+      }
+      closeRun();
+      run = [row];
+      chainEndMs = row.endMs;
+    }
+    closeRun();
+  }
+
+  return bursts;
+}
+
+function chunk<T>(values: T[], size: number): T[][] {
+  const chunks: T[][] = [];
+  for (let i = 0; i < values.length; i += size) {
+    chunks.push(values.slice(i, i + size));
+  }
+  return chunks;
+}
+
+function buildSamples(
+  db: DatabaseSync,
+  bursts: DuplicateSubtitleLineBurst[],
+  sampleLimit: number,
+): DuplicateSubtitleLineSample[] {
+  if (sampleLimit === 0 || bursts.length === 0) {
+    return [];
+  }
+  const largest = [...bursts]
+    .sort((a, b) => b.removedLineIds.length - a.removedLineIds.length)
+    .slice(0, sampleLimit);
+  const videoIds = [...new Set(largest.map((burst) => burst.videoId))];
+  const titles = new Map<number, string>();
+  for (const batch of chunk(videoIds, ID_BATCH_SIZE)) {
+    const rows = db
+      .prepare(
+        `SELECT video_id AS videoId, canonical_title AS title
+         FROM imm_videos
+         WHERE video_id IN (${makePlaceholders(batch)})`,
+      )
+      .all(...batch) as Array<{ videoId: number; title: string | null }>;
+    for (const row of rows) {
+      if (row.title) titles.set(row.videoId, row.title);
+    }
+  }
+
+  return largest.map((burst) => ({
+    videoId: burst.videoId,
+    videoTitle: titles.get(burst.videoId) ?? null,
+    text: burst.text,
+    frames: burst.removedLineIds.length + 1,
+    removedLines: burst.removedLineIds.length,
+    startMs: burst.startMs,
+    endMs: burst.endMs,
+  }));
+}
+
+function sumRemovedOccurrences(
+  db: DatabaseSync,
+  table: 'imm_word_line_occurrences' | 'imm_kanji_line_occurrences',
+  lineIds: number[],
+): number {
+  let total = 0;
+  for (const batch of chunk(lineIds, ID_BATCH_SIZE)) {
+    const row = db
+      .prepare(
+        `SELECT COALESCE(SUM(occurrence_count), 0) AS total
+         FROM ${table}
+         WHERE line_id IN (${makePlaceholders(batch)})`,
+      )
+      .get(...batch) as { total: number } | null;
+    total += row?.total ?? 0;
+  }
+  return total;
+}
+
+function applyBursts(db: DatabaseSync, bursts: DuplicateSubtitleLineBurst[]): void {
+  const removedLineIds = bursts.flatMap((burst) => burst.removedLineIds);
+  const currentMs = toDbTimestamp(nowMs());
+
+  db.exec('BEGIN IMMEDIATE');
+  try {
+    for (const batch of chunk(removedLineIds, ID_BATCH_SIZE)) {
+      const placeholders = makePlaceholders(batch);
+      // Measured before the delete, applied after it: `applyLexicalRemovals` checks the
+      // surviving occurrences to decide whether a zeroed count really means the word is
+      // gone, so the rows it inspects have to be the post-delete ones.
+      const plan = planLexicalRemovalsForLines(db, batch);
+      db.prepare(`DELETE FROM imm_word_line_occurrences WHERE line_id IN (${placeholders})`).run(
+        ...batch,
+      );
+      db.prepare(`DELETE FROM imm_kanji_line_occurrences WHERE line_id IN (${placeholders})`).run(
+        ...batch,
+      );
+      db.prepare(`DELETE FROM imm_subtitle_lines WHERE line_id IN (${placeholders})`).run(...batch);
+      applyLexicalRemovals(db, plan);
+    }
+
+    const extendStmt = db.prepare(
+      `UPDATE imm_subtitle_lines
+       SET segment_end_ms = ?, LAST_UPDATE_DATE = ?
+       WHERE line_id = ? AND (segment_end_ms IS NULL OR segment_end_ms < ?)`,
+    );
+    for (const burst of bursts) {
+      extendStmt.run(burst.endMs, currentMs, burst.keptLineId, burst.endMs);
+    }
+    db.exec('COMMIT');
+  } catch (error) {
+    try {
+      db.exec('ROLLBACK');
+    } catch {
+      // Surface the transaction failure, not the rollback's.
+    }
+    throw error;
+  }
+}
+
+/**
+ * Collapse stored animation bursts down to one line each.
+ *
+ * A dry run measures exactly what an apply would remove, using the same scan, so the
+ * numbers shown in a confirmation prompt are the numbers that will happen.
+ */
+export function cleanupDuplicateSubtitleLines(
+  db: DatabaseSync,
+  options: DuplicateSubtitleLineCleanupOptions = {},
+): DuplicateSubtitleLineCleanupSummary {
+  const bounds = resolveBounds(options);
+  const dryRun = options.dryRun === true;
+  const rows = readCandidateLines(db, bounds);
+  const bursts = findDuplicateSubtitleLineBursts(rows, options);
+  const removedLineIds = bursts.flatMap((burst) => burst.removedLineIds);
+
+  const summary: DuplicateSubtitleLineCleanupSummary = {
+    dryRun,
+    lookbackDays: bounds.lookbackDays,
+    scannedLines: rows.length,
+    burstGroups: bursts.length,
+    removedLines: removedLineIds.length,
+    removedWordOccurrences: sumRemovedOccurrences(db, 'imm_word_line_occurrences', removedLineIds),
+    removedKanjiOccurrences: sumRemovedOccurrences(
+      db,
+      'imm_kanji_line_occurrences',
+      removedLineIds,
+    ),
+    samples: buildSamples(db, bursts, bounds.sampleLimit),
+  };
+
+  if (dryRun || removedLineIds.length === 0) {
+    return summary;
+  }
+
+  applyBursts(db, bursts);
+  return summary;
+}

src/core/services/immersion-tracker/query-shared.ts

@@ -276,6 +276,19 @@ export function planLexicalRemovalsForSessions(
   return planLexicalRemovals(db, `sl.session_id IN (${makePlaceholders(sessionIds)})`, sessionIds);
 }
 
+/**
+ * Measure what deleting these individual subtitle lines removes from the vocabulary
+ * tables. Used by the duplicate-line cleanup, which drops animation frames out of the
+ * middle of sessions that otherwise stay intact.
+ */
+export function planLexicalRemovalsForLines(
+  db: DatabaseSync,
+  lineIds: number[],
+): LexicalRemovalPlan {
+  if (lineIds.length === 0) return EMPTY_LEXICAL_REMOVAL_PLAN;
+  return planLexicalRemovals(db, `sl.line_id IN (${makePlaceholders(lineIds)})`, lineIds);
+}
+
 /** Measure what deleting these videos removes from the vocabulary tables. */
 export function planLexicalRemovalsForVideos(
   db: DatabaseSync,

src/core/services/stats-server/library-routes.ts

@@ -5,6 +5,7 @@ import {
   buildSentenceSearchOptions,
   enrichSessionsWithKnownWordMetrics,
   parseBooleanQuery,
+  parseDuplicateLineCleanupBody,
   parseExcludedWordsBody,
   parseIntQuery,
 } from './route-support.js';
@@ -40,6 +41,19 @@ export function registerStatsLibraryRoutes(
     return c.json(statsJson('setExcludedWords', { ok: true }));
   });
 
+  // Collapse animation bursts older versions recorded frame by frame. `dryRun` measures
+  // the same scan without writing, so the confirmation the user sees is the real cost.
+  app.post('/api/stats/maintenance/duplicate-lines', async (c) => {
+    const contentType = c.req.header('content-type')?.split(';', 1)[0]?.trim().toLowerCase();
+    if (contentType !== 'application/json') return c.body(null, 415);
+    const body = await c.req.json().catch(() => null);
+    const options = parseDuplicateLineCleanupBody(body);
+    if (!options) return c.body(null, 400);
+    const { dryRun, lookbackDays } = options;
+    const result = await tracker.cleanupDuplicateSubtitleLines({ dryRun, lookbackDays });
+    return c.json(statsJson('duplicateLineCleanup', result));
+  });
+
   app.get('/api/stats/vocabulary/occurrences', async (c) => {
     const headword = (c.req.query('headword') ?? '').trim();
     const word = (c.req.query('word') ?? '').trim();

src/core/services/stats-server/route-support.ts

@@ -88,6 +88,35 @@ export function parseExcludedWordsBody(body: unknown): StatsExcludedWord[] | nul
   return words;
 }
 
+/**
+ * Read a duplicate-line cleanup request. An explicit object with no lookback scans all
+ * history. Invalid bodies and invalid windows are rejected instead of broadening scope.
+ */
+export function parseDuplicateLineCleanupBody(body: unknown): {
+  dryRun: boolean;
+  lookbackDays: number | null;
+} | null {
+  if (!body || typeof body !== 'object' || Array.isArray(body)) {
+    return null;
+  }
+  const source = body as Record<string, unknown>;
+  if (source.dryRun !== undefined && typeof source.dryRun !== 'boolean') {
+    return null;
+  }
+  const rawLookback = source.lookbackDays;
+  if (
+    rawLookback !== undefined &&
+    rawLookback !== null &&
+    (typeof rawLookback !== 'number' || !Number.isFinite(rawLookback) || rawLookback < 1)
+  ) {
+    return null;
+  }
+  return {
+    dryRun: source.dryRun === true,
+    lookbackDays: typeof rawLookback === 'number' ? Math.floor(rawLookback) : null,
+  };
+}
+
 export function loadKnownWordsSet(cachePath: string | undefined): Set<string> | null {
   if (!cachePath || !existsSync(cachePath)) return null;
   try {

src/core/services/subtitle-burst-constants.ts

@@ -0,0 +1,48 @@
+/*
+ * Thresholds that decide when a run of repeated subtitle events is one animation.
+ *
+ * Three consumers have to agree on these numbers or the same karaoke line is one cue in
+ * the sidebar and two hundred in the stats: the file-level cue dedup
+ * (`subtitle-cue-dedup`), the live gate that decides what immersion stats record
+ * (`subtitle-line-dedup-gate`), and the retroactive database cleanup
+ * (`immersion-tracker/duplicate-line-cleanup`).
+ */
+
+/**
+ * Back-to-back frames of the same animation are authored flush against each other; a
+ * tiny tolerance absorbs the centisecond rounding of the ASS timestamp format.
+ */
+export const DUPLICATE_CUE_GAP_TOLERANCE_SECONDS = 0.05;
+
+/**
+ * A burst is a *sequence*. Two adjacent events are two events, not an animation --
+ * characters do repeat each other, and a repeated line can legitimately be short.
+ */
+export const MIN_BURST_EVENTS = 3;
+
+/**
+ * Real dialogue holds on screen for about a second, so a run with a couple of much
+ * shorter events among them looks like frames. Used only alongside authoring evidence.
+ */
+export const ANIMATION_FRAME_MAX_SECONDS = 0.3;
+
+/** A karaoke run usually ends on a long "hold" frame, so not every event is short. */
+export const MIN_TAGGED_BURST_FRAMES = 2;
+
+/**
+ * SRT and VTT carry no authoring metadata at all, so timing is the only signal available
+ * -- which makes it the easiest one to get wrong. ASS->SRT conversion leaves frames at
+ * ~0.04s, well under any real utterance, and a burst leaves many of them behind. Both
+ * bounds are deliberately far stricter than the ASS path: a run of ordinary short lines
+ * (`えっ` traded between characters) must not clear them.
+ */
+export const TIMING_ONLY_FRAME_MAX_SECONDS = 0.1;
+export const MIN_TIMING_ONLY_FRAMES = 5;
+
+/**
+ * The live gate can only recognise a streaming burst from the inside, so it records the
+ * first `MIN_TIMING_ONLY_FRAMES - 1` frames before it starts dropping. That stored
+ * residue is one frame short of the timing-only minimum, and the retroactive cleanup
+ * accepts it only when every event also sits under the strict timing-only frame bound.
+ */
+export const MIN_STREAM_RESIDUE_FRAMES = MIN_TIMING_ONLY_FRAMES - 1;

src/core/services/subtitle-cue-dedup.ts

@@ -7,31 +7,20 @@
  */
 
 import { hasAssTemporalOverride, isAnimatedAssEffectKind } from './ass-text';
+import {
+  ANIMATION_FRAME_MAX_SECONDS,
+  DUPLICATE_CUE_GAP_TOLERANCE_SECONDS,
+  MIN_BURST_EVENTS,
+  MIN_TAGGED_BURST_FRAMES,
+  MIN_TIMING_ONLY_FRAMES,
+  TIMING_ONLY_FRAME_MAX_SECONDS,
+} from './subtitle-burst-constants';
 import type {
   AnnotatedSubtitleCue,
   SubtitleCue,
   SubtitleSourceFormat,
 } from './subtitle-cue-parser';
 
-// Back-to-back frames of the same animation are authored flush against each other; a
-// tiny tolerance absorbs the centisecond rounding of the ASS timestamp format.
-const DUPLICATE_CUE_GAP_TOLERANCE_SECONDS = 0.05;
-// A burst is a *sequence*. Two adjacent events are two events, not an animation --
-// characters do repeat each other, and a repeated line can legitimately be short.
-const MIN_BURST_EVENTS = 3;
-// Real dialogue holds on screen for about a second, so a run with a couple of much
-// shorter events among them looks like frames. Used only alongside authoring evidence.
-const ANIMATION_FRAME_MAX_SECONDS = 0.3;
-// A karaoke run usually ends on a long "hold" frame, so not every event is short.
-const MIN_TAGGED_BURST_FRAMES = 2;
-// SRT and VTT carry no authoring metadata at all, so timing is the only signal available
-// -- which makes it the easiest one to get wrong. ASS->SRT conversion leaves frames at
-// ~0.04s, well under any real utterance, and a burst leaves many of them behind. Both
-// bounds are deliberately far stricter than the ASS path: a run of ordinary short lines
-// (`えっ` traded between characters) must not clear them.
-const TIMING_ONLY_FRAME_MAX_SECONDS = 0.1;
-const MIN_TIMING_ONLY_FRAMES = 5;
-
 function cueKey(cue: SubtitleCue): string {
   return `${cue.startTime}|${cue.endTime}|${cue.text}`;
 }

src/core/services/subtitle-line-dedup-gate.test.ts

@@ -0,0 +1,204 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createSubtitleLineDedupGate } from './subtitle-line-dedup-gate';
+import type { SubtitleCue } from '../../types';
+
+function karaokeFrames(text: string, start: number, frames: number, frameSeconds: number) {
+  return Array.from({ length: frames }, (_, index) => ({
+    text,
+    startSec: start + index * frameSeconds,
+    endSec: start + (index + 1) * frameSeconds,
+  }));
+}
+
+test('parsed cues drop the frames the sidebar already collapsed', () => {
+  // What `mergeDuplicateCues` leaves behind for a karaoke run: one cue over the run.
+  const cues: SubtitleCue[] = [
+    { startTime: 10, endTime: 14, text: '飛び上がる' },
+    { startTime: 14, endTime: 16, text: 'もしも' },
+  ];
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => cues });
+
+  const recorded = karaokeFrames('飛び上がる', 10, 40, 0.04).filter((sample) =>
+    gate.shouldRecord(sample),
+  );
+
+  assert.equal(recorded.length, 1);
+  assert.equal(recorded[0]!.startSec, 10);
+  assert.equal(gate.shouldRecord({ text: 'もしも', startSec: 14, endSec: 16 }), true);
+});
+
+test('parsed cues keep separate lines that merely repeat', () => {
+  const cues: SubtitleCue[] = [
+    { startTime: 3, endTime: 3.4, text: 'えっ' },
+    { startTime: 3.4, endTime: 3.9, text: 'えっ' },
+    { startTime: 3.9, endTime: 4.5, text: 'えっ' },
+  ];
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => cues });
+
+  const recorded = cues.filter((cue) =>
+    gate.shouldRecord({ text: cue.text, startSec: cue.startTime, endSec: cue.endTime }),
+  );
+
+  assert.equal(recorded.length, 3);
+});
+
+test('parsed cues outrank the streaming heuristic for short repeated cues', () => {
+  // Long enough to trip the timing-only rule, but the parser saw these with full
+  // lookahead and kept them, so every one of them is a line the sidebar shows.
+  const cues: SubtitleCue[] = Array.from({ length: 8 }, (_, index) => ({
+    startTime: 3 + index * 0.08,
+    endTime: 3 + (index + 1) * 0.08,
+    text: 'えっ',
+  }));
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => cues });
+
+  const recorded = cues.filter((cue) =>
+    gate.shouldRecord({ text: cue.text, startSec: cue.startTime, endSec: cue.endTime }),
+  );
+
+  assert.equal(recorded.length, 8);
+});
+
+test('parsed cues preserve legitimately separate cues only 40ms apart', () => {
+  const cues: SubtitleCue[] = Array.from({ length: 8 }, (_, index) => ({
+    startTime: 3 + index * 0.04,
+    endTime: 3 + (index + 1) * 0.04,
+    text: 'えっ',
+  }));
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => cues });
+
+  const recorded = cues.filter((cue) =>
+    gate.shouldRecord({ text: cue.text, startSec: cue.startTime, endSec: cue.endTime }),
+  );
+
+  assert.equal(recorded.length, 8);
+});
+
+test('a line whose timing does not match any cue still records', () => {
+  // A shifted track, an embedded sub nobody parsed: no match, no drop.
+  const cues: SubtitleCue[] = [{ startTime: 10, endTime: 14, text: '飛び上がる' }];
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => cues });
+
+  assert.equal(gate.shouldRecord({ text: '飛び上がる', startSec: 42, endSec: 44 }), true);
+});
+
+test('shifted parsed text falls back to streaming burst detection', () => {
+  const cues: SubtitleCue[] = [{ startTime: 10, endTime: 14, text: '飛び上がる' }];
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => cues });
+
+  const recorded = karaokeFrames('飛び上がる', 42, 40, 0.04).filter((sample) =>
+    gate.shouldRecord(sample),
+  );
+
+  assert.equal(recorded.length, 4);
+});
+
+test('replacing the parsed cue source forgets a streaming run', () => {
+  let cues: SubtitleCue[] = [];
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => cues });
+
+  karaokeFrames('飛び上がる', 42, 20, 0.04).forEach((sample) => gate.shouldRecord(sample));
+  // A new source publishes its own cue list; the old run must not carry over.
+  cues = [{ startTime: 100, endTime: 104, text: 'もしも' }];
+
+  assert.equal(gate.shouldRecord({ text: '飛び上がる', startSec: 42.8, endSec: 42.84 }), true);
+});
+
+test('without parsed cues a long run of identical short frames stops recording', () => {
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => null });
+
+  const recorded = karaokeFrames('ひとしずく', 0, 200, 0.04).filter((sample) =>
+    gate.shouldRecord(sample),
+  );
+
+  assert.equal(recorded.length, 4);
+});
+
+test('without parsed cues interleaved dual-line karaoke stops recording per line', () => {
+  // Fansub OPs typically run two typeset lines at once -- kanji and romaji -- and mpv
+  // reports their frames interleaved. Each line must build its own run.
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => null });
+
+  const samples = Array.from({ length: 40 }, (_, index) => {
+    const start = 10 + Math.floor(index / 2) * 0.06;
+    return index % 2 === 0
+      ? { text: '歌詞', startSec: start, endSec: start + 0.06 }
+      : { text: 'kashi', startSec: start + 0.001, endSec: start + 0.061 };
+  });
+  const recorded = samples.filter((sample) => gate.shouldRecord(sample));
+
+  assert.equal(recorded.filter((sample) => sample.text === '歌詞').length, 4);
+  assert.equal(recorded.filter((sample) => sample.text === 'kashi').length, 4);
+});
+
+test('interleaved dialogue between two speakers keeps recording', () => {
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => null });
+
+  // Two characters trading normal-length lines back and forth.
+  const samples = Array.from({ length: 12 }, (_, index) => {
+    const start = 5 + index * 0.7;
+    return {
+      text: index % 2 === 0 ? 'えっ' : 'なに',
+      startSec: start,
+      endSec: start + 0.7,
+    };
+  });
+  const recorded = samples.filter((sample) => gate.shouldRecord(sample));
+
+  assert.equal(recorded.length, 12);
+});
+
+test('without parsed cues ordinary repeated dialogue keeps recording', () => {
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => null });
+
+  // Six contiguous `えっ`, each held for a normal beat rather than an animation frame.
+  const recorded = karaokeFrames('えっ', 0, 6, 0.6).filter((sample) => gate.shouldRecord(sample));
+
+  assert.equal(recorded.length, 6);
+});
+
+test('the same event offered twice does not advance the run', () => {
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => null });
+
+  // mpv fires the timing handler once for `sub-start` and once for `sub-end`.
+  for (let i = 0; i < 8; i += 1) {
+    assert.equal(gate.shouldRecord({ text: '待って', startSec: 5, endSec: 5.05 }), true);
+  }
+});
+
+test('a gap between frames starts a new run', () => {
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => null });
+
+  const first = karaokeFrames('もし', 0, 6, 0.04).filter((sample) => gate.shouldRecord(sample));
+  const second = karaokeFrames('もし', 30, 6, 0.04).filter((sample) => gate.shouldRecord(sample));
+
+  assert.equal(first.length, 4);
+  assert.equal(second.length, 4);
+});
+
+test('reset forgets the streaming run', () => {
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => null });
+
+  karaokeFrames('もし', 0, 20, 0.04).forEach((sample) => gate.shouldRecord(sample));
+  gate.reset();
+
+  assert.equal(gate.shouldRecord({ text: 'もし', startSec: 0.8, endSec: 0.84 }), true);
+});
+
+test('reset ignores stale parsed cues until the source publishes a new cue list', () => {
+  let cues: SubtitleCue[] = [{ startTime: 10, endTime: 14, text: '飛び上がる' }];
+  const gate = createSubtitleLineDedupGate({ getParsedCues: () => cues });
+
+  assert.equal(gate.shouldRecord({ text: '飛び上がる', startSec: 10, endSec: 10.04 }), true);
+  gate.reset();
+
+  const recordedWithStaleCues = karaokeFrames('飛び上がる', 10.04, 8, 0.04).filter((sample) =>
+    gate.shouldRecord(sample),
+  );
+  assert.equal(recordedWithStaleCues.length, 4);
+
+  cues = [{ startTime: 20, endTime: 24, text: '飛び上がる' }];
+  assert.equal(gate.shouldRecord({ text: '飛び上がる', startSec: 20, endSec: 20.04 }), true);
+  assert.equal(gate.shouldRecord({ text: '飛び上がる', startSec: 20.04, endSec: 20.08 }), false);
+});

src/core/services/subtitle-line-dedup-gate.ts

@@ -0,0 +1,241 @@
+/*
+ * Decides which live mpv subtitle lines reach the immersion stats.
+ *
+ * The sidebar reads a parsed subtitle file, so it can collapse an animation burst with
+ * full lookahead (`subtitle-cue-dedup`). Stats are fed from mpv's `sub-start`/`sub-end`
+ * properties instead -- one event per animation frame, each with its own start time --
+ * so without a gate a karaoke OP counts its lyrics once per frame and buries every real
+ * word in the vocabulary charts.
+ *
+ * Two layers, in order:
+ *
+ * 1. When the active source has been parsed, its cue list has *already* been collapsed.
+ *    A live line that lands inside a surviving cue of the same text, but after that
+ *    cue's start, is a frame the sidebar merged away, so stats drop it too. This is the
+ *    layer that keeps the two views consistent by construction.
+ * 2. Otherwise (embedded track nobody parsed, a source whose timings mpv has shifted)
+ *    fall back to timing alone. No authoring metadata is available live -- mpv delivers
+ *    `sub-text-ass` after `sub-start`/`sub-end`, so any ASS text read here belongs to the
+ *    previous event -- which puts this layer in the same position as the SRT path in
+ *    `subtitle-cue-dedup`, and it uses that path's deliberately strict bounds.
+ */
+
+import { normalizePlainSubtitleText } from './ass-text';
+import {
+  DUPLICATE_CUE_GAP_TOLERANCE_SECONDS,
+  MIN_TIMING_ONLY_FRAMES,
+  TIMING_ONLY_FRAME_MAX_SECONDS,
+} from './subtitle-burst-constants';
+import type { SubtitleCue } from './subtitle-cue-parser';
+
+export interface SubtitleLineSample {
+  text: string;
+  startSec: number;
+  endSec: number;
+}
+
+export interface SubtitleLineDedupGateDeps {
+  /** Cues for the active source, already collapsed by the parser. */
+  getParsedCues: () => readonly SubtitleCue[] | null | undefined;
+}
+
+export interface SubtitleLineDedupGate {
+  /** False when this line is an animation frame of a line already recorded. */
+  shouldRecord: (sample: SubtitleLineSample) => boolean;
+  /** Forget run state and ignore the current cue list until its source is replaced. */
+  reset: () => void;
+}
+
+interface CueSpan {
+  startTime: number;
+  endTime: number;
+}
+
+interface StreamingRunState {
+  startMs: number;
+  chainEndSec: number;
+  /** Contiguous identical short frames seen so far, including the recorded first one. */
+  frames: number;
+}
+
+/**
+ * Dual-line karaoke interleaves two texts frame by frame, so runs are tracked per text.
+ * Dead runs are pruned as playback moves past them; the cap only matters after a
+ * backward seek leaves runs whose ends sit ahead of the new position.
+ */
+const MAX_ACTIVE_STREAMING_RUNS = 32;
+
+/** Exact cue identity, separate from the looser tolerance used to chain adjacent frames. */
+const CUE_START_IDENTITY_TOLERANCE_SECONDS = 0.005;
+
+function normalizeLineText(text: string): string {
+  return normalizePlainSubtitleText(text, { collapseLineBreaks: true });
+}
+
+function buildSpansByText(cues: readonly SubtitleCue[]): Map<string, CueSpan[]> {
+  const spansByText = new Map<string, CueSpan[]>();
+  for (const cue of cues) {
+    const key = normalizeLineText(cue.text);
+    if (!key) continue;
+    const span = { startTime: cue.startTime, endTime: cue.endTime };
+    const existing = spansByText.get(key);
+    if (existing) {
+      existing.push(span);
+    } else {
+      spansByText.set(key, [span]);
+    }
+  }
+  return spansByText;
+}
+
+/**
+ * A frame the parser merged away: the same text, starting inside a surviving cue but
+ * after it began.
+ *
+ * Starting a cue always wins over falling inside one. The first frame of a collapsed run
+ * starts *at* the merged cue, and a line the parser deliberately kept separate -- three
+ * characters trading `えっ` back to back -- begins exactly where the one before it ends.
+ */
+function isMergedAwayFrame(spans: readonly CueSpan[], startSec: number): boolean | null {
+  const coveringSpans = spans.filter(
+    (span) =>
+      startSec >= span.startTime - CUE_START_IDENTITY_TOLERANCE_SECONDS &&
+      startSec <= span.endTime + CUE_START_IDENTITY_TOLERANCE_SECONDS,
+  );
+  if (coveringSpans.length === 0) {
+    return null;
+  }
+  const startsOwnCue = spans.some(
+    (span) => Math.abs(startSec - span.startTime) <= CUE_START_IDENTITY_TOLERANCE_SECONDS,
+  );
+  if (startsOwnCue) {
+    return false;
+  }
+  return coveringSpans.some(
+    (span) =>
+      startSec > span.startTime + CUE_START_IDENTITY_TOLERANCE_SECONDS &&
+      startSec <= span.endTime + CUE_START_IDENTITY_TOLERANCE_SECONDS,
+  );
+}
+
+export function createSubtitleLineDedupGate(
+  deps: SubtitleLineDedupGateDeps,
+): SubtitleLineDedupGate {
+  let indexedCues: readonly SubtitleCue[] | null | undefined;
+  let ignoredCuesAfterReset: readonly SubtitleCue[] | null | undefined;
+  let spansByText: Map<string, CueSpan[]> = new Map();
+  const runs = new Map<string, StreamingRunState>();
+
+  const lookupSpans = (text: string): CueSpan[] | null => {
+    const cues = deps.getParsedCues() ?? null;
+    if (ignoredCuesAfterReset !== undefined) {
+      if (cues === ignoredCuesAfterReset) {
+        return null;
+      }
+      ignoredCuesAfterReset = undefined;
+    }
+    if (cues !== indexedCues) {
+      indexedCues = cues;
+      spansByText = cues?.length ? buildSpansByText(cues) : new Map();
+      runs.clear();
+    }
+    return spansByText.get(text) ?? null;
+  };
+
+  /**
+   * A run this sample cannot continue is a run no later sample can continue either --
+   * continuation needs a start inside the running end plus tolerance, and starts only
+   * move forward outside of seeks.
+   */
+  const pruneDeadRuns = (startSec: number): void => {
+    for (const [text, state] of runs) {
+      if (state.chainEndSec + DUPLICATE_CUE_GAP_TOLERANCE_SECONDS < startSec) {
+        runs.delete(text);
+      }
+    }
+  };
+
+  /**
+   * Timing-only burst detection over a stream. Without lookahead the run can only be
+   * recognised from the inside, so the first frames of a burst are recorded and the rest
+   * dropped -- an OP costs a handful of counted lines instead of several hundred.
+   */
+  const advanceStreamingRun = (text: string, sample: SubtitleLineSample): boolean => {
+    pruneDeadRuns(sample.startSec);
+    const startMs = Math.round(sample.startSec * 1000);
+    const run = runs.get(text);
+    // mpv reports `sub-start` and `sub-end` separately, so one event can be offered
+    // twice. The same start is the same frame, never the next one in a run.
+    if (run && run.startMs === startMs) {
+      run.chainEndSec = Math.max(run.chainEndSec, sample.endSec);
+      return run.frames < MIN_TIMING_ONLY_FRAMES;
+    }
+
+    const isShortFrame = sample.endSec - sample.startSec < TIMING_ONLY_FRAME_MAX_SECONDS;
+    // Frames are authored flush against each other, but typesetters do overlap them, so
+    // the chain only requires forward progress that stays inside the running end.
+    const continuesRun =
+      run !== undefined &&
+      isShortFrame &&
+      startMs > run.startMs &&
+      sample.startSec <= run.chainEndSec + DUPLICATE_CUE_GAP_TOLERANCE_SECONDS;
+
+    if (continuesRun && run) {
+      run.startMs = startMs;
+      run.chainEndSec = Math.max(run.chainEndSec, sample.endSec);
+      run.frames += 1;
+      return run.frames < MIN_TIMING_ONLY_FRAMES;
+    }
+
+    const fresh: StreamingRunState = {
+      startMs,
+      chainEndSec: sample.endSec,
+      frames: isShortFrame ? 1 : 0,
+    };
+    runs.set(text, fresh);
+    if (runs.size > MAX_ACTIVE_STREAMING_RUNS) {
+      let oldestText: string | undefined;
+      let oldestEnd = Infinity;
+      for (const [runText, state] of runs) {
+        if (runText !== text && state.chainEndSec < oldestEnd) {
+          oldestEnd = state.chainEndSec;
+          oldestText = runText;
+        }
+      }
+      if (oldestText !== undefined) {
+        runs.delete(oldestText);
+      }
+    }
+    return fresh.frames < MIN_TIMING_ONLY_FRAMES;
+  };
+
+  return {
+    shouldRecord: (sample) => {
+      const text = normalizeLineText(sample.text);
+      if (!text) {
+        return true;
+      }
+
+      // The parsed cue list has the final say wherever it covers this line. Falling
+      // through to the streaming heuristic would let it drop cues the parser looked at
+      // with full lookahead and deliberately kept apart, which is the disagreement
+      // between sidebar and stats this gate exists to prevent.
+      const spans = lookupSpans(text);
+      if (spans) {
+        const mergedAway = isMergedAwayFrame(spans, sample.startSec);
+        if (mergedAway !== null) {
+          runs.delete(text);
+          return !mergedAway;
+        }
+      }
+
+      return advanceStreamingRun(text, sample);
+    },
+    reset: () => {
+      runs.clear();
+      ignoredCuesAfterReset = deps.getParsedCues() ?? null;
+      indexedCues = undefined;
+      spansByText = new Map();
+    },
+  };
+}

src/main/runtime/mpv-main-event-main-deps.test.ts

@@ -267,3 +267,123 @@ test('flushPlaybackPositionOnMediaPathClear ignores disconnected mpv time-pos re
 
   assert.deepEqual(recorded, [42]);
 });
+
+test('media and subtitle-track transitions reset live subtitle-line deduplication', () => {
+  const recordedStarts: number[] = [];
+  const handlers = createBuildBindMpvMainEventHandlersMainDepsHandler({
+    appState: {
+      initialArgs: null,
+      overlayRuntimeInitialized: true,
+      mpvClient: null,
+      immersionTracker: {
+        recordSubtitleLine: (_text: string, start: number) => recordedStarts.push(start),
+      },
+      subtitleTimingTracker: null,
+      activeParsedSubtitleCues: null,
+      currentMediaPath: '/video-a.mkv',
+      currentSubText: '',
+      currentSubAssText: '',
+      playbackPaused: null,
+      previousSecondarySubVisibility: false,
+    },
+    getQuitOnDisconnectArmed: () => false,
+    scheduleQuitCheck: () => {},
+    quitApp: () => {},
+    reportJellyfinRemoteStopped: () => {},
+    syncOverlayMpvSubtitleSuppression: () => {},
+    maybeRunAnilistPostWatchUpdate: async () => {},
+    logSubtitleTimingError: () => {},
+    broadcastToOverlayWindows: () => {},
+    onSubtitleChange: () => {},
+    ensureImmersionTrackerInitialized: () => {},
+    updateCurrentMediaPath: () => {},
+    restoreMpvSubVisibility: () => {},
+    resetSubtitleSidebarEmbeddedLayout: () => {},
+    getCurrentAnilistMediaKey: () => null,
+    resetAnilistMediaTracking: () => {},
+    maybeProbeAnilistDuration: () => {},
+    ensureAnilistMediaGuess: () => {},
+    syncImmersionMediaState: () => {},
+    updateCurrentMediaTitle: () => {},
+    resetAnilistMediaGuessState: () => {},
+    reportJellyfinRemoteProgress: () => {},
+    updateSubtitleRenderMetrics: () => {},
+    refreshDiscordPresence: () => {},
+  })();
+
+  for (let index = 0; index < 8; index += 1) {
+    handlers.recordImmersionSubtitleLine('待って', index * 0.04, (index + 1) * 0.04);
+  }
+  assert.equal(recordedStarts.length, 4);
+
+  handlers.updateCurrentMediaPath('/video-b.mkv');
+  handlers.recordImmersionSubtitleLine('待って', 0.32, 0.36);
+  assert.equal(recordedStarts.length, 5);
+
+  for (let index = 9; index < 16; index += 1) {
+    handlers.recordImmersionSubtitleLine('待って', index * 0.04, (index + 1) * 0.04);
+  }
+  assert.equal(recordedStarts.length, 8);
+
+  assert.equal(typeof handlers.onSubtitleTrackChange, 'function');
+  handlers.onSubtitleTrackChange?.(2);
+  handlers.recordImmersionSubtitleLine('待って', 0.64, 0.68);
+  assert.equal(recordedStarts.length, 9);
+});
+
+test('subtitle-track transitions ignore stale parsed cues until replacement cues arrive', () => {
+  const recordedStarts: number[] = [];
+  const appState = {
+    initialArgs: null,
+    overlayRuntimeInitialized: true,
+    mpvClient: null,
+    immersionTracker: {
+      recordSubtitleLine: (_text: string, start: number) => recordedStarts.push(start),
+    },
+    subtitleTimingTracker: null,
+    activeParsedSubtitleCues: [{ startTime: 10, endTime: 14, text: '飛び上がる' }],
+    currentMediaPath: '/video-a.mkv',
+    currentSubText: '',
+    currentSubAssText: '',
+    playbackPaused: null,
+    previousSecondarySubVisibility: false,
+  };
+  const handlers = createBuildBindMpvMainEventHandlersMainDepsHandler({
+    appState,
+    getQuitOnDisconnectArmed: () => false,
+    scheduleQuitCheck: () => {},
+    quitApp: () => {},
+    reportJellyfinRemoteStopped: () => {},
+    syncOverlayMpvSubtitleSuppression: () => {},
+    maybeRunAnilistPostWatchUpdate: async () => {},
+    logSubtitleTimingError: () => {},
+    broadcastToOverlayWindows: () => {},
+    onSubtitleChange: () => {},
+    ensureImmersionTrackerInitialized: () => {},
+    updateCurrentMediaPath: () => {},
+    restoreMpvSubVisibility: () => {},
+    resetSubtitleSidebarEmbeddedLayout: () => {},
+    getCurrentAnilistMediaKey: () => null,
+    resetAnilistMediaTracking: () => {},
+    maybeProbeAnilistDuration: () => {},
+    ensureAnilistMediaGuess: () => {},
+    syncImmersionMediaState: () => {},
+    updateCurrentMediaTitle: () => {},
+    resetAnilistMediaGuessState: () => {},
+    reportJellyfinRemoteProgress: () => {},
+    updateSubtitleRenderMetrics: () => {},
+    refreshDiscordPresence: () => {},
+  })();
+
+  handlers.recordImmersionSubtitleLine('飛び上がる', 10, 10.04);
+  handlers.onSubtitleTrackChange?.(2);
+  for (let index = 1; index <= 8; index += 1) {
+    handlers.recordImmersionSubtitleLine('飛び上がる', 10 + index * 0.04, 10 + (index + 1) * 0.04);
+  }
+  assert.equal(recordedStarts.length, 5);
+
+  appState.activeParsedSubtitleCues = [{ startTime: 20, endTime: 24, text: '飛び上がる' }];
+  handlers.recordImmersionSubtitleLine('飛び上がる', 20, 20.04);
+  handlers.recordImmersionSubtitleLine('飛び上がる', 20.04, 20.08);
+  assert.deepEqual(recordedStarts.slice(-1), [20]);
+});

src/main/runtime/mpv-main-event-main-deps.ts

@@ -1,4 +1,5 @@
-import type { MergedToken, SubtitleData } from '../../types';
+import { createSubtitleLineDedupGate } from '../../core/services/subtitle-line-dedup-gate';
+import type { MergedToken, SubtitleCue, SubtitleData } from '../../types';
 
 type AnilistPostWatchRunOptions = {
   watchedSeconds?: number;
@@ -34,6 +35,7 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
     subtitleTimingTracker: {
       recordSubtitle?: (text: string, start: number, end: number, secondaryText?: string) => void;
     } | null;
+    activeParsedSubtitleCues?: SubtitleCue[] | null;
     currentMediaPath?: string | null;
     currentSubText: string;
     currentSubAssText: string;
@@ -86,6 +88,11 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
     deps.ensureImmersionTrackerInitialized();
     deps.appState.immersionTracker?.recordPlaybackPosition?.(normalizedTimeSec);
   };
+  // mpv reports every animation frame of a typeset line as its own subtitle event, so
+  // stats have to collapse bursts the same way the parsed cue list already does.
+  const immersionLineDedupGate = createSubtitleLineDedupGate({
+    getParsedCues: () => deps.appState.activeParsedSubtitleCues,
+  });
   const hasInitialPlaybackQuitOnDisconnectArg = (): boolean =>
     Boolean(
       deps.appState.initialArgs?.managedPlayback ||
@@ -110,6 +117,9 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
       if (!tracker?.recordSubtitleLine) {
         return;
       }
+      if (!immersionLineDedupGate.shouldRecord({ text, startSec: start, endSec: end })) {
+        return;
+      }
       const secondaryText = deps.appState.mpvClient?.currentSecondarySubText || null;
       const cachedTokens =
         deps.appState.currentSubtitleData?.text === text
@@ -159,9 +169,10 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
     logSubtitleProcessingDebug: deps.logSubtitleProcessingDebug
       ? (message: string) => deps.logSubtitleProcessingDebug!(message)
       : undefined,
-    onSubtitleTrackChange: deps.onSubtitleTrackChange
-      ? (sid: number | null) => deps.onSubtitleTrackChange!(sid)
-      : undefined,
+    onSubtitleTrackChange: (sid: number | null) => {
+      immersionLineDedupGate.reset();
+      deps.onSubtitleTrackChange?.(sid);
+    },
     onSubtitleTrackListChange: deps.onSubtitleTrackListChange
       ? (trackList: unknown[] | null) => deps.onSubtitleTrackListChange!(trackList)
       : undefined,
@@ -173,7 +184,10 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
       deps.broadcastToOverlayWindows('subtitle-ass:set', text),
     broadcastSecondarySubtitle: (text: string) =>
       deps.broadcastToOverlayWindows('secondary-subtitle:set', text),
-    updateCurrentMediaPath: (path: string) => deps.updateCurrentMediaPath(path),
+    updateCurrentMediaPath: (path: string) => {
+      immersionLineDedupGate.reset();
+      deps.updateCurrentMediaPath(path);
+    },
     restoreMpvSubVisibility: () => deps.restoreMpvSubVisibility(),
     resetSubtitleSidebarEmbeddedLayout: () => deps.resetSubtitleSidebarEmbeddedLayout?.(),
     getCurrentAnilistMediaKey: () => deps.getCurrentAnilistMediaKey(),

src/main/runtime/stats-cli-command.test.ts

@@ -200,6 +200,59 @@ test('stats cli command fails when immersion tracking is disabled', async () =>
   ]);
 });
 
+test('stats cli command runs a duplicate-line cleanup preview without touching the dashboard', async () => {
+  const { handler, calls, responses } = makeHandler({
+    getImmersionTracker: () => ({
+      cleanupDuplicateSubtitleLines: async (options: {
+        dryRun?: boolean;
+        lookbackDays?: number | null;
+      }) => ({
+        dryRun: options.dryRun === true,
+        lookbackDays: options.lookbackDays ?? null,
+        scannedLines: 900,
+        burstGroups: 2,
+        removedLines: 180,
+        removedWordOccurrences: 540,
+        removedKanjiOccurrences: 120,
+        samples: [
+          {
+            videoId: 7,
+            videoTitle: 'Ep 1',
+            text: '飛び上がる',
+            frames: 90,
+            removedLines: 89,
+            startMs: 1000,
+            endMs: 5000,
+          },
+        ],
+      }),
+    }),
+  });
+
+  await handler(
+    {
+      statsResponsePath: '/tmp/subminer-stats-response.json',
+      statsCleanup: true,
+      statsCleanupDuplicateLines: true,
+      statsCleanupDryRun: true,
+      statsCleanupLookbackDays: 30,
+    },
+    'initial',
+  );
+
+  assert.deepEqual(calls, [
+    'ensureImmersionTrackerStarted',
+    'info:Stats duplicate-line cleanup preview (last 30d): scanned=900 bursts=2 removedLines=180 removedWordCounts=540 removedKanjiCounts=120',
+    'info:  Ep 1: "飛び上がる" x90',
+  ]);
+  assert.deepEqual(responses, [
+    {
+      responsePath: '/tmp/subminer-stats-response.json',
+      payload: { ok: true },
+    },
+  ]);
+});
+
 test('stats cli command runs vocab cleanup instead of opening dashboard when cleanup mode is requested', async () => {
   const { handler, calls, responses } = makeHandler({
     getImmersionTracker: () => ({

src/main/runtime/stats-cli-command.ts

@@ -1,6 +1,7 @@
 import fs from 'node:fs';
 import path from 'node:path';
 import type { CliArgs, CliCommandSource } from '../../cli/args';
+import type { DuplicateSubtitleLineCleanupSummary } from '../../core/services/immersion-tracker/duplicate-line-cleanup';
 import type {
   LifetimeRebuildSummary,
   VocabularyCleanupSummary,
@@ -50,6 +51,10 @@ export function createRunStatsCliCommandHandler(deps: {
   ensureVocabularyCleanupTokenizerReady?: () => Promise<void> | void;
   getImmersionTracker: () => {
     cleanupVocabularyStats?: () => Promise<VocabularyCleanupSummary>;
+    cleanupDuplicateSubtitleLines?: (options: {
+      dryRun?: boolean;
+      lookbackDays?: number | null;
+    }) => Promise<DuplicateSubtitleLineCleanupSummary>;
     rebuildLifetimeSummaries?: () => Promise<LifetimeRebuildSummary>;
   } | null;
   ensureStatsServerStarted: () => string;
@@ -83,6 +88,9 @@ export function createRunStatsCliCommandHandler(deps: {
       | 'statsCleanup'
       | 'statsCleanupVocab'
       | 'statsCleanupLifetime'
+      | 'statsCleanupDuplicateLines'
+      | 'statsCleanupDryRun'
+      | 'statsCleanupLookbackDays'
     >,
     source: CliCommandSource,
   ): Promise<void> => {
@@ -126,6 +134,7 @@ export function createRunStatsCliCommandHandler(deps: {
         const cleanupModes = [
           args.statsCleanupVocab ? 'vocab' : null,
           args.statsCleanupLifetime ? 'lifetime' : null,
+          args.statsCleanupDuplicateLines ? 'duplicate-lines' : null,
         ].filter(Boolean);
         if (cleanupModes.length !== 1) {
           throw new Error('Choose exactly one stats cleanup mode.');
@@ -142,6 +151,27 @@ export function createRunStatsCliCommandHandler(deps: {
           writeResponseSafe(args.statsResponsePath, { ok: true });
           return;
         }
+        if (args.statsCleanupDuplicateLines && tracker.cleanupDuplicateSubtitleLines) {
+          const result = await tracker.cleanupDuplicateSubtitleLines({
+            dryRun: args.statsCleanupDryRun === true,
+            lookbackDays: args.statsCleanupLookbackDays ?? null,
+          });
+          const window =
+            result.lookbackDays === null ? 'all history' : `last ${result.lookbackDays}d`;
+          deps.logInfo(
+            `Stats duplicate-line cleanup ${result.dryRun ? 'preview' : 'complete'} (${window}): ` +
+              `scanned=${result.scannedLines} bursts=${result.burstGroups} ` +
+              `removedLines=${result.removedLines} removedWordCounts=${result.removedWordOccurrences} ` +
+              `removedKanjiCounts=${result.removedKanjiOccurrences}`,
+          );
+          for (const sample of result.samples.slice(0, 5)) {
+            deps.logInfo(
+              `  ${sample.videoTitle ?? `video ${sample.videoId}`}: "${sample.text}" x${sample.frames}`,
+            );
+          }
+          writeResponseSafe(args.statsResponsePath, { ok: true });
+          return;
+        }
         if (!args.statsCleanupLifetime || !tracker.rebuildLifetimeSummaries) {
           throw new Error('Stats cleanup mode is not available.');
         }

src/media-generator.test.ts

@@ -4,13 +4,18 @@ import * as os from 'node:os';
 import * as path from 'node:path';
 import test from 'node:test';
 
-import { buildAnimatedImageVideoFilter, MediaGenerator } from './media-generator';
+import {
+  AUDIO_GENERATION_TIMEOUT_MS,
+  buildAnimatedImageVideoFilter,
+  MediaGenerator,
+  type MediaGeneratorOptions,
+} from './media-generator';
 
 async function withStubbedFfmpeg(
   run: (generator: MediaGenerator, argsPath: string) => Promise<void>,
-  options: {
-    logDebug?: (message: string) => void;
-    now?: () => number;
+  options: MediaGeneratorOptions = {},
+  stubOptions: {
+    skipOutput?: boolean;
   } = {},
 ): Promise<void> {
   const root = fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-media-generator-test-'));
@@ -31,7 +36,9 @@ async function withStubbedFfmpeg(
       '}',
       "fs.writeFileSync(process.env.SUBMINER_TEST_FFMPEG_ARGS, JSON.stringify(args), 'utf8');",
       'const outputPath = args.at(-1);',
+      "if (process.env.SUBMINER_TEST_FFMPEG_SKIP_OUTPUT !== '1') {",
       "  fs.writeFileSync(outputPath, 'avif', 'utf8');",
+      '}',
     ].join('\n'),
     'utf8',
   );
@@ -46,8 +53,14 @@ async function withStubbedFfmpeg(
 
   const originalPath = process.env.PATH;
   const originalArgsPath = process.env.SUBMINER_TEST_FFMPEG_ARGS;
+  const originalSkipOutput = process.env.SUBMINER_TEST_FFMPEG_SKIP_OUTPUT;
   process.env.PATH = `${binDir}${path.delimiter}${originalPath ?? ''}`;
   process.env.SUBMINER_TEST_FFMPEG_ARGS = argsPath;
+  if (stubOptions.skipOutput) {
+    process.env.SUBMINER_TEST_FFMPEG_SKIP_OUTPUT = '1';
+  } else {
+    delete process.env.SUBMINER_TEST_FFMPEG_SKIP_OUTPUT;
+  }
   const generator = new MediaGenerator(tempDir, options);
 
   try {
@@ -60,6 +73,11 @@ async function withStubbedFfmpeg(
     } else {
       process.env.SUBMINER_TEST_FFMPEG_ARGS = originalArgsPath;
     }
+    if (originalSkipOutput === undefined) {
+      delete process.env.SUBMINER_TEST_FFMPEG_SKIP_OUTPUT;
+    } else {
+      process.env.SUBMINER_TEST_FFMPEG_SKIP_OUTPUT = originalSkipOutput;
+    }
     fs.rmSync(root, { recursive: true, force: true });
   }
 }
@@ -316,6 +334,65 @@ test('generateAudio keeps explicit audio stream maps for normal media paths', as
   });
 });
 
+test('generateAudio bounds probing when the selected local audio stream is known', async () => {
+  await withStubbedFfmpeg(async (generator, argsPath) => {
+    await generator.generateAudio('/video.mkv', 10, 12, 0, 2);
+
+    const args = readFfmpegArgs(argsPath);
+    const inputIndex = args.indexOf('-i');
+    assert.ok(args.indexOf('-probesize') > -1);
+    assert.ok(args.indexOf('-probesize') < inputIndex);
+    assert.equal(args[args.indexOf('-probesize') + 1], '32768');
+    assert.ok(args.indexOf('-analyzeduration') < inputIndex);
+    assert.equal(args[args.indexOf('-analyzeduration') + 1], '0');
+  });
+});
+
+test('generateAudio retains normal probing for non-Matroska local media', async () => {
+  await withStubbedFfmpeg(async (generator, argsPath) => {
+    await generator.generateAudio('/video.mp4', 10, 12, 0, 2);
+
+    const args = readFfmpegArgs(argsPath);
+    assert.equal(args.includes('-probesize'), false);
+    assert.equal(args.includes('-analyzeduration'), false);
+  });
+});
+
+test('generateAudio retains a two-minute extraction timeout', async () => {
+  let observedTimeout: number | undefined;
+
+  await withStubbedFfmpeg(
+    async (generator) => {
+      await generator.generateAudio('/video.mp4', 10, 12);
+    },
+    {
+      execFile: (_file, args, options, callback) => {
+        observedTimeout = options.timeout;
+        const outputPath = args.at(-1);
+        assert.ok(outputPath);
+        fs.writeFileSync(outputPath, 'mp3', 'utf8');
+        queueMicrotask(() => callback(null));
+      },
+    },
+  );
+
+  assert.equal(AUDIO_GENERATION_TIMEOUT_MS, 120_000);
+  assert.equal(observedTimeout, AUDIO_GENERATION_TIMEOUT_MS);
+});
+
+test('generateAudio reports when ffmpeg exits without creating output', async () => {
+  await withStubbedFfmpeg(
+    async (generator) => {
+      await assert.rejects(
+        generator.generateAudio('/video.mp4', 10, 12),
+        /FFmpeg audio generation failed: FFmpeg exited without creating an output file/,
+      );
+    },
+    {},
+    { skipOutput: true },
+  );
+});
+
 test('generateAudio debug-logs cached input and completion timing', async () => {
   const logs: string[] = [];
   const times = [1000, 1052];

src/media-generator.ts

@@ -26,9 +26,17 @@ import { normalizeMediaInput, type MediaInput } from './media-input';
 const log = createLogger('media');
 const AUDIO_NORMALIZATION_FILTER = 'loudnorm=I=-23:TP=-2:LRA=11';
 const AUDIO_AMPLIFICATION_LIMITER_FILTER = 'alimiter=limit=0.891251:level=false';
+export const AUDIO_GENERATION_TIMEOUT_MS = 120_000;
 
 export type { MediaInput, MediaInputOptions } from './media-input';
 
+type MediaGeneratorExecFile = (
+  file: string,
+  args: readonly string[],
+  options: { timeout: number },
+  callback: (error: ExecFileException | null) => void,
+) => void;
+
 function normalizeAnimatedImageFps(fps: number | undefined): number {
   const fallbackFps = 10;
   const safeFps = typeof fps === 'number' && Number.isFinite(fps) ? fps : fallbackFps;
@@ -77,6 +85,7 @@ export function buildAnimatedImageVideoFilter(options: {
 export interface MediaGeneratorOptions {
   logDebug?: (message: string) => void;
   now?: () => number;
+  execFile?: MediaGeneratorExecFile;
 }
 
 function sanitizeDebugToken(value: string, fallback: string): string {
@@ -274,6 +283,14 @@ export class MediaGenerator {
     const duration = endTime - start + safePadding;
     const mediaInput = normalizeMediaInput(videoPath);
     const inputDescription = describeMediaInputForDebugLog(videoPath);
+    const hasSelectedAudioStream =
+      !mediaInput.singleResolvedStream &&
+      typeof audioStreamIndex === 'number' &&
+      Number.isInteger(audioStreamIndex) &&
+      audioStreamIndex >= 0;
+    const isLocalMatroskaMedia =
+      !/^[A-Za-z][A-Za-z\d+.-]*:\/\//.test(mediaInput.path) &&
+      /\.(?:mkv|mka|mks|webm)$/i.test(mediaInput.path);
 
     return new Promise((resolve, reject) => {
       const outputPath = this.createTempOutputPath('audio', 'mp3');
@@ -284,16 +301,14 @@ export class MediaGenerator {
         '-t',
         duration.toString(),
         ...mediaInput.inputArgs,
+        ...(hasSelectedAudioStream && isLocalMatroskaMedia
+          ? ['-probesize', '32768', '-analyzeduration', '0']
+          : []),
         '-i',
         mediaInput.path,
       ];
 
-      if (
-        !mediaInput.singleResolvedStream &&
-        typeof audioStreamIndex === 'number' &&
-        Number.isInteger(audioStreamIndex) &&
-        audioStreamIndex >= 0
-      ) {
+      if (hasSelectedAudioStream) {
         args.push('-map', `0:${audioStreamIndex}`);
       }
 
@@ -321,7 +336,8 @@ export class MediaGenerator {
       this.logMediaDebug(
         `audio start ${inputDescription} start=${start} duration=${duration} padding=${safePadding}`,
       );
-      execFile('ffmpeg', args, { timeout: 30000 }, (error) => {
+      const runExecFile: MediaGeneratorExecFile = this.options.execFile ?? execFile;
+      runExecFile('ffmpeg', args, { timeout: AUDIO_GENERATION_TIMEOUT_MS }, (error) => {
         if (error) {
           this.logMediaDebug(
             `audio failed ${inputDescription} elapsedMs=${this.elapsedMs(startedAt)} ${describeFfmpegFailureForDebugLog(error)}`,
@@ -338,8 +354,16 @@ export class MediaGenerator {
           );
           resolve(data);
         } catch (err) {
+          if ((err as NodeJS.ErrnoException).code === 'ENOENT') {
+            reject(
+              new Error(
+                'FFmpeg audio generation failed: FFmpeg exited without creating an output file.',
+              ),
+            );
+          } else {
             reject(err);
           }
+        }
       });
     });
   }

src/types/stats-http-contract.ts

@@ -18,6 +18,7 @@ import type {
   SessionTimelinePoint,
   StatsAnkiNoteInfo,
   StatsCoverImagesData,
+  StatsDuplicateLineCleanupResult,
   StatsExcludedWord,
   StreakCalendarDay,
   TrendsDashboardData,
@@ -31,6 +32,13 @@ export type StatsTrendRange = '7d' | '30d' | '90d' | '365d' | 'all';
 export type StatsTrendGroupBy = 'day' | 'month';
 export type StatsMineMode = 'word' | 'sentence' | 'audio';
 
+/** Body of `POST /api/stats/maintenance/duplicate-lines`. */
+export interface StatsDuplicateLineCleanupRequest {
+  dryRun?: boolean;
+  /** Null means every recorded line, whatever its age. */
+  lookbackDays?: number | null;
+}
+
 export interface StatsSessionKnownWordsTimelinePoint {
   linesSeen: number;
   knownWordsSeen: number;
@@ -125,6 +133,7 @@ export interface StatsJsonResponseMap {
   vocabulary: VocabularyEntry[];
   excludedWords: StatsExcludedWord[];
   setExcludedWords: StatsOkResponse;
+  duplicateLineCleanup: StatsDuplicateLineCleanupResult;
   wordOccurrences: VocabularyOccurrenceEntry[];
   sentenceSearch: SentenceSearchResult[];
   kanji: KanjiEntry[];
@@ -178,6 +187,9 @@ export interface StatsHttpClient {
   getVocabulary: (limit?: number) => Promise<VocabularyEntry[]>;
   getExcludedWords: () => Promise<StatsExcludedWord[]>;
   setExcludedWords: (words: StatsExcludedWord[]) => Promise<void>;
+  cleanupDuplicateLines: (
+    options?: StatsDuplicateLineCleanupRequest,
+  ) => Promise<StatsDuplicateLineCleanupResult>;
   getWordOccurrences: (
     headword: string,
     word: string,

src/types/stats-wire.ts

@@ -82,6 +82,29 @@ export interface StatsExcludedWord {
   reading: string;
 }
 
+/** One animation burst the duplicate-line cleanup found in the stats database. */
+export interface StatsDuplicateLineSample {
+  videoId: number;
+  videoTitle: string | null;
+  text: string;
+  /** Events recorded for this run, including the one that is kept. */
+  frames: number;
+  removedLines: number;
+  startMs: number;
+  endMs: number;
+}
+
+export interface StatsDuplicateLineCleanupResult {
+  dryRun: boolean;
+  lookbackDays: number | null;
+  scannedLines: number;
+  burstGroups: number;
+  removedLines: number;
+  removedWordOccurrences: number;
+  removedKanjiOccurrences: number;
+  samples: StatsDuplicateLineSample[];
+}
+
 export interface StatsCoverImage {
   contentType: string;
   dataUrl: string;

stats/src/components/vocabulary/DuplicateLineCleanup.test.tsx

@@ -0,0 +1,254 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { Window } from 'happy-dom';
+import { act } from 'react';
+import { createRoot } from 'react-dom/client';
+import { apiClient } from '../../lib/api-client';
+import type { StatsDuplicateLineCleanupResult } from '../../types/stats';
+import { DuplicateLineCleanup } from './DuplicateLineCleanup';
+
+interface TestWindow extends Window {
+  IS_REACT_ACT_ENVIRONMENT?: boolean;
+}
+
+function installDom(): () => void {
+  const previousWindow = globalThis.window;
+  const previousDocument = globalThis.document;
+  const previousHTMLElement = globalThis.HTMLElement;
+  const previousISReactActEnvironment = (
+    globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean }
+  ).IS_REACT_ACT_ENVIRONMENT;
+  const window = new Window() as TestWindow;
+
+  Object.defineProperty(globalThis, 'window', { value: window, configurable: true });
+  Object.defineProperty(globalThis, 'document', { value: window.document, configurable: true });
+  Object.defineProperty(globalThis, 'HTMLElement', {
+    value: window.HTMLElement,
+    configurable: true,
+  });
+  (
+    globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean }
+  ).IS_REACT_ACT_ENVIRONMENT = true;
+
+  return () => {
+    Object.defineProperty(globalThis, 'window', { value: previousWindow, configurable: true });
+    Object.defineProperty(globalThis, 'document', { value: previousDocument, configurable: true });
+    Object.defineProperty(globalThis, 'HTMLElement', {
+      value: previousHTMLElement,
+      configurable: true,
+    });
+    (
+      globalThis as typeof globalThis & { IS_REACT_ACT_ENVIRONMENT?: boolean }
+    ).IS_REACT_ACT_ENVIRONMENT = previousISReactActEnvironment;
+  };
+}
+
+function findButton(container: Element, label: string): HTMLButtonElement {
+  const match = [...container.querySelectorAll('button')].find(
+    (button) => (button.textContent ?? '').trim() === label,
+  );
+  assert.ok(match, `expected a "${label}" button`);
+  return match as unknown as HTMLButtonElement;
+}
+
+/** The backdrop stays clickable during an apply, so it reaches the guard in `close`. */
+function findBackdrop(container: Element): HTMLButtonElement {
+  const match = container.querySelector('button[aria-label="Close duplicate line cleanup"]');
+  assert.ok(match, 'expected the backdrop close button');
+  return match as unknown as HTMLButtonElement;
+}
+
+function deferred<T>(): { promise: Promise<T>; resolve: (value: T) => void } {
+  let resolve!: (value: T) => void;
+  const promise = new Promise<T>((done) => {
+    resolve = done;
+  });
+  return { promise, resolve };
+}
+
+function summary(
+  overrides: Partial<StatsDuplicateLineCleanupResult> = {},
+): StatsDuplicateLineCleanupResult {
+  return {
+    dryRun: false,
+    lookbackDays: 30,
+    scannedLines: 900,
+    burstGroups: 2,
+    removedLines: 180,
+    removedWordOccurrences: 540,
+    removedKanjiOccurrences: 120,
+    samples: [],
+    ...overrides,
+  };
+}
+
+interface Harness {
+  container: Element;
+  cleanedCalls: () => number;
+  closedCalls: () => number;
+  teardown: () => void;
+}
+
+async function mount(cleanup: (typeof apiClient)['cleanupDuplicateLines']): Promise<Harness> {
+  const uninstallDom = installDom();
+  const originalCleanup = apiClient.cleanupDuplicateLines;
+  apiClient.cleanupDuplicateLines = cleanup;
+
+  let cleaned = 0;
+  let closed = 0;
+  const container = document.createElement('div');
+  document.body.append(container);
+  const root = createRoot(container);
+
+  await act(async () => {
+    root.render(
+      <DuplicateLineCleanup
+        onClose={() => {
+          closed += 1;
+        }}
+        onCleaned={() => {
+          cleaned += 1;
+        }}
+      />,
+    );
+  });
+
+  return {
+    container,
+    cleanedCalls: () => cleaned,
+    closedCalls: () => closed,
+    teardown: () => {
+      apiClient.cleanupDuplicateLines = originalCleanup;
+      uninstallDom();
+    },
+  };
+}
+
+test('a reload is still owed after a later scan replaces the applied result', async () => {
+  const harness = await mount(async ({ dryRun } = {}) => summary({ dryRun: dryRun === true }));
+
+  try {
+    await act(async () => {
+      findButton(harness.container, 'Scan').click();
+    });
+    await act(async () => {
+      findButton(harness.container, 'Clean Up').click();
+    });
+    assert.equal(harness.cleanedCalls(), 0, 'reload must wait for the result to be read');
+
+    // The follow-up scan clears the applied summary, but the rows are already gone.
+    await act(async () => {
+      findButton(harness.container, 'Scan').click();
+    });
+    await act(async () => {
+      findButton(harness.container, 'Close').click();
+    });
+
+    assert.equal(harness.cleanedCalls(), 1);
+    assert.equal(harness.closedCalls(), 1);
+  } finally {
+    harness.teardown();
+  }
+});
+
+test('a reload is still owed after the lookback window changes', async () => {
+  const harness = await mount(async ({ dryRun } = {}) => summary({ dryRun: dryRun === true }));
+
+  try {
+    await act(async () => {
+      findButton(harness.container, 'Scan').click();
+    });
+    await act(async () => {
+      findButton(harness.container, 'Clean Up').click();
+    });
+    await act(async () => {
+      findButton(harness.container, '7 days').click();
+    });
+    await act(async () => {
+      findButton(harness.container, 'Close').click();
+    });
+
+    assert.equal(harness.cleanedCalls(), 1);
+  } finally {
+    harness.teardown();
+  }
+});
+
+test('closing is refused while an apply is in flight', async () => {
+  const pending = deferred<StatsDuplicateLineCleanupResult>();
+  const harness = await mount(async ({ dryRun } = {}) =>
+    dryRun === true ? summary({ dryRun: true }) : pending.promise,
+  );
+
+  try {
+    await act(async () => {
+      findButton(harness.container, 'Scan').click();
+    });
+    await act(async () => {
+      findButton(harness.container, 'Clean Up').click();
+    });
+
+    assert.equal(findButton(harness.container, 'Close').disabled, true);
+    // The backdrop is never disabled, so this is the path that has to be refused.
+    await act(async () => {
+      findBackdrop(harness.container).click();
+    });
+    assert.equal(harness.closedCalls(), 0, 'the modal must stay open mid-apply');
+    assert.equal(harness.cleanedCalls(), 0);
+
+    await act(async () => {
+      pending.resolve(summary({ removedLines: 12 }));
+      await pending.promise;
+    });
+    await act(async () => {
+      findButton(harness.container, 'Close').click();
+    });
+
+    assert.equal(harness.closedCalls(), 1);
+    assert.equal(harness.cleanedCalls(), 1);
+  } finally {
+    harness.teardown();
+  }
+});
+
+test('a scan on its own owes no reload', async () => {
+  const harness = await mount(async ({ dryRun } = {}) => summary({ dryRun: dryRun === true }));
+
+  try {
+    await act(async () => {
+      findButton(harness.container, 'Scan').click();
+    });
+    await act(async () => {
+      findButton(harness.container, 'Close').click();
+    });
+
+    assert.equal(harness.cleanedCalls(), 0);
+    assert.equal(harness.closedCalls(), 1);
+  } finally {
+    harness.teardown();
+  }
+});
+
+test('an apply that removes nothing owes no reload', async () => {
+  // The scan saw work to do, but by the time it ran another cleanup had taken it.
+  const harness = await mount(async ({ dryRun } = {}) =>
+    dryRun === true ? summary({ dryRun: true }) : summary({ burstGroups: 0, removedLines: 0 }),
+  );
+
+  try {
+    await act(async () => {
+      findButton(harness.container, 'Scan').click();
+    });
+    await act(async () => {
+      findButton(harness.container, 'Clean Up').click();
+    });
+    await act(async () => {
+      findButton(harness.container, 'Close').click();
+    });
+
+    assert.equal(harness.cleanedCalls(), 0);
+    assert.equal(harness.closedCalls(), 1);
+  } finally {
+    harness.teardown();
+  }
+});

stats/src/components/vocabulary/DuplicateLineCleanup.tsx

@@ -0,0 +1,202 @@
+import { useCallback, useState } from 'react';
+import { getStatsClient } from '../../hooks/useStatsApi';
+import { formatNumber } from '../../lib/formatters';
+import type { StatsDuplicateLineCleanupResult } from '../../types/stats';
+
+interface DuplicateLineCleanupProps {
+  onClose: () => void;
+  /** Called after rows are actually removed, so the charts can reload. */
+  onCleaned: () => void;
+}
+
+const LOOKBACK_CHOICES: Array<{ label: string; days: number | null }> = [
+  { label: '7 days', days: 7 },
+  { label: '30 days', days: 30 },
+  { label: '90 days', days: 90 },
+  { label: '1 year', days: 365 },
+  { label: 'All time', days: null },
+];
+
+function formatTimecode(ms: number): string {
+  const totalSeconds = Math.max(0, Math.floor(ms / 1000));
+  const minutes = Math.floor(totalSeconds / 60);
+  const seconds = totalSeconds % 60;
+  return `${minutes}:${String(seconds).padStart(2, '0')}`;
+}
+
+export function DuplicateLineCleanup({ onClose, onCleaned }: DuplicateLineCleanupProps) {
+  const [lookbackDays, setLookbackDays] = useState<number | null>(30);
+  const [preview, setPreview] = useState<StatsDuplicateLineCleanupResult | null>(null);
+  const [applied, setApplied] = useState<StatsDuplicateLineCleanupResult | null>(null);
+  const [busy, setBusy] = useState<'scan' | 'apply' | null>(null);
+  const [error, setError] = useState<string | null>(null);
+  // Survives everything the displayed result does not: another scan, a different window.
+  // Rows are gone from the moment an apply succeeds, so the reload is owed until it runs.
+  const [needsReload, setNeedsReload] = useState(false);
+
+  const run = useCallback(
+    async (dryRun: boolean) => {
+      setBusy(dryRun ? 'scan' : 'apply');
+      setError(null);
+      try {
+        const result = await getStatsClient().cleanupDuplicateLines({ dryRun, lookbackDays });
+        if (dryRun) {
+          setPreview(result);
+          setApplied(null);
+        } else {
+          setApplied(result);
+          setPreview(null);
+          if (result.removedLines > 0) {
+            setNeedsReload(true);
+          }
+        }
+      } catch (cause) {
+        setError(cause instanceof Error ? cause.message : String(cause));
+      } finally {
+        setBusy(null);
+      }
+    },
+    [lookbackDays],
+  );
+
+  // Reloading the vocabulary tables unmounts this modal along with the rest of the tab,
+  // so it waits for the user to close: they get to read what was removed first. Closing
+  // is refused mid-apply, which would drop the reload on the floor along with the report.
+  const close = useCallback(() => {
+    if (busy === 'apply') {
+      return;
+    }
+    if (needsReload) {
+      onCleaned();
+    }
+    onClose();
+  }, [busy, needsReload, onCleaned, onClose]);
+
+  const result = applied ?? preview;
+  const nothingToDo = preview !== null && preview.removedLines === 0;
+
+  return (
+    <div className="fixed inset-0 z-50">
+      <button
+        type="button"
+        aria-label="Close duplicate line cleanup"
+        className="absolute inset-0 bg-ctp-crust/70 backdrop-blur-[2px]"
+        onClick={close}
+      />
+      <div className="absolute inset-x-0 top-1/2 mx-auto max-w-xl -translate-y-1/2 rounded-xl border border-ctp-surface1 bg-ctp-mantle shadow-2xl">
+        <div className="flex items-center justify-between border-b border-ctp-surface1 px-5 py-4">
+          <h2 className="text-sm font-semibold text-ctp-text">Duplicate Lines</h2>
+          <button
+            type="button"
+            disabled={busy === 'apply'}
+            className="rounded-md border border-ctp-surface2 px-3 py-1.5 text-xs font-medium text-ctp-subtext0 transition hover:border-ctp-blue hover:text-ctp-blue disabled:opacity-50"
+            onClick={close}
+          >
+            Close
+          </button>
+        </div>
+
+        <div className="space-y-4 px-5 py-4">
+          <p className="text-xs leading-relaxed text-ctp-subtext0">
+            Typeset subtitles — karaoke openings, animated signs — are authored as one event per
+            animation frame, and older versions counted every frame as its own line. This finds
+            those runs and collapses each one back to a single line, giving back the word and kanji
+            counts they inflated. Ordinary repeated dialogue is left alone.
+          </p>
+
+          <div>
+            <div className="mb-2 text-xs font-medium text-ctp-subtext1">Look back over</div>
+            <div className="flex flex-wrap gap-2">
+              {LOOKBACK_CHOICES.map((choice) => (
+                <button
+                  key={choice.label}
+                  type="button"
+                  disabled={busy !== null}
+                  onClick={() => {
+                    setLookbackDays(choice.days);
+                    setPreview(null);
+                    setApplied(null);
+                  }}
+                  className={`rounded-lg border px-3 py-1.5 text-xs transition disabled:opacity-50 ${
+                    lookbackDays === choice.days
+                      ? 'border-ctp-blue/50 bg-ctp-surface2 text-ctp-text'
+                      : 'border-ctp-surface1 bg-ctp-surface0 text-ctp-overlay2 hover:text-ctp-subtext0'
+                  }`}
+                >
+                  {choice.label}
+                </button>
+              ))}
+            </div>
+          </div>
+
+          {error && (
+            <div className="rounded-lg border border-ctp-red/30 bg-ctp-red/10 px-3 py-2 text-xs text-ctp-red">
+              {error}
+            </div>
+          )}
+
+          {result && (
+            <div className="rounded-lg bg-ctp-surface0 px-4 py-3">
+              <div className="text-sm text-ctp-text">
+                {applied
+                  ? `Removed ${formatNumber(applied.removedLines)} repeated lines`
+                  : nothingToDo
+                    ? 'No animation bursts found in this window'
+                    : `Found ${formatNumber(preview!.burstGroups)} bursts covering ${formatNumber(preview!.removedLines)} extra lines`}
+              </div>
+              <div className="mt-1 text-xs text-ctp-overlay2">
+                {formatNumber(result.scannedLines)} lines scanned ·{' '}
+                {formatNumber(result.removedWordOccurrences)} word counts ·{' '}
+                {formatNumber(result.removedKanjiOccurrences)} kanji counts
+                {applied ? ' removed' : ' would be removed'}
+              </div>
+
+              {result.samples.length > 0 && (
+                <div className="mt-3 max-h-52 space-y-1.5 overflow-y-auto">
+                  {result.samples.map((sample) => (
+                    <div
+                      key={`${sample.videoId}:${sample.startMs}:${sample.text}`}
+                      className="flex items-center justify-between gap-3 rounded-md bg-ctp-mantle px-3 py-1.5"
+                    >
+                      <div className="min-w-0">
+                        <div className="truncate text-xs text-ctp-text">{sample.text}</div>
+                        <div className="truncate text-[11px] text-ctp-overlay1">
+                          {sample.videoTitle ?? `Video ${sample.videoId}`} ·{' '}
+                          {formatTimecode(sample.startMs)}
+                        </div>
+                      </div>
+                      <span className="shrink-0 text-xs text-ctp-peach">×{sample.frames}</span>
+                    </div>
+                  ))}
+                </div>
+              )}
+            </div>
+          )}
+
+          <div className="flex items-center justify-end gap-2">
+            <button
+              type="button"
+              disabled={busy !== null}
+              onClick={() => void run(true)}
+              className="rounded-md border border-ctp-surface2 px-3 py-1.5 text-xs font-medium text-ctp-subtext0 transition hover:border-ctp-blue hover:text-ctp-blue disabled:opacity-50"
+            >
+              {busy === 'scan' ? 'Scanning…' : 'Scan'}
+            </button>
+            <button
+              type="button"
+              disabled={busy !== null || preview === null || nothingToDo}
+              onClick={() => void run(false)}
+              className="rounded-md border border-ctp-red/30 px-3 py-1.5 text-xs font-medium text-ctp-red transition hover:bg-ctp-red/10 disabled:opacity-40"
+            >
+              {busy === 'apply' ? 'Cleaning…' : 'Clean Up'}
+            </button>
+          </div>
+          <p className="text-[11px] text-ctp-overlay1">
+            Scan first: cleanup removes rows and cannot be undone. Session watch time and lines-seen
+            totals are left untouched.
+          </p>
+        </div>
+      </div>
+    </div>
+  );
+}

stats/src/components/vocabulary/VocabularyTab.tsx

@@ -5,6 +5,7 @@ import { WordList } from './WordList';
 import { KanjiBreakdown } from './KanjiBreakdown';
 import { KanjiDetailPanel } from './KanjiDetailPanel';
 import { ExclusionManager } from './ExclusionManager';
+import { DuplicateLineCleanup } from './DuplicateLineCleanup';
 import { formatNumber } from '../../lib/formatters';
 import { TrendChart } from '../trends/TrendChart';
 import { FrequencyRankTable } from './FrequencyRankTable';
@@ -34,10 +35,11 @@ export function VocabularyTab({
   onRemoveExclusion,
   onClearExclusions,
 }: VocabularyTabProps) {
-  const { words, kanji, knownWords, loading, error } = useVocabulary();
+  const { words, kanji, knownWords, loading, error, reload } = useVocabulary();
   const [selectedKanjiId, setSelectedKanjiId] = useState<number | null>(null);
   const [hideNames, setHideNames] = useState(false);
   const [showExclusionManager, setShowExclusionManager] = useState(false);
+  const [showDuplicateLineCleanup, setShowDuplicateLineCleanup] = useState(false);
 
   const hasNames = useMemo(() => words.some(isProperNoun), [words]);
   const filteredWords = useMemo(() => {
@@ -129,6 +131,13 @@ export function VocabularyTab({
             Hide Names
           </button>
         )}
+        <button
+          type="button"
+          onClick={() => setShowDuplicateLineCleanup(true)}
+          className="shrink-0 rounded-lg border border-ctp-surface1 bg-ctp-surface0 px-3 py-2 text-xs text-ctp-overlay2 transition-colors hover:text-ctp-subtext0"
+        >
+          Duplicates
+        </button>
         <button
           type="button"
           onClick={() => setShowExclusionManager(true)}
@@ -193,6 +202,13 @@ export function VocabularyTab({
           onClose={() => setShowExclusionManager(false)}
         />
       )}
+
+      {showDuplicateLineCleanup && (
+        <DuplicateLineCleanup
+          onClose={() => setShowDuplicateLineCleanup(false)}
+          onCleaned={reload}
+        />
+      )}
     </div>
   );
 }

stats/src/hooks/useVocabulary.ts

@@ -1,4 +1,4 @@
-import { useState, useEffect } from 'react';
+import { useState, useEffect, useCallback } from 'react';
 import { getStatsClient } from './useStatsApi';
 import type { VocabularyEntry, KanjiEntry } from '../types/stats';
 
@@ -8,6 +8,9 @@ export function useVocabulary() {
   const [knownWords, setKnownWords] = useState<Set<string>>(new Set());
   const [loading, setLoading] = useState(true);
   const [error, setError] = useState<string | null>(null);
+  // Bumped by `reload` after maintenance rewrites the vocabulary tables.
+  const [reloadToken, setReloadToken] = useState(0);
+  const reload = useCallback(() => setReloadToken((token) => token + 1), []);
 
   useEffect(() => {
     let cancelled = false;
@@ -46,7 +49,7 @@ export function useVocabulary() {
     return () => {
       cancelled = true;
     };
-  }, []);
+  }, [reloadToken]);
 
-  return { words, kanji, knownWords, loading, error };
+  return { words, kanji, knownWords, loading, error, reload };
 }

stats/src/lib/api-client.ts

@@ -6,6 +6,8 @@ import type {
   StatsAnkiNotesInfoRequest,
   StatsCoverImagesRequest,
   StatsDeleteSessionsRequest,
+  StatsDuplicateLineCleanupRequest,
+  StatsDuplicateLineCleanupResult,
   StatsExcludedWordsRequest,
   StatsHttpClient,
   StatsJsonResponseMap,
@@ -102,6 +104,19 @@ export const apiClient = {
       body: JSON.stringify({ words } satisfies StatsExcludedWordsRequest),
     });
   },
+  cleanupDuplicateLines: async (
+    options: StatsDuplicateLineCleanupRequest = {},
+  ): Promise<StatsDuplicateLineCleanupResult> => {
+    const res = await fetchResponse('/api/stats/maintenance/duplicate-lines', {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
+        dryRun: options.dryRun === true,
+        lookbackDays: options.lookbackDays ?? null,
+      } satisfies StatsDuplicateLineCleanupRequest),
+    });
+    return res.json() as Promise<StatsDuplicateLineCleanupResult>;
+  },
   getWordOccurrences: (headword: string, word: string, reading: string, limit = 50, offset = 0) =>
     fetchJson(
       'wordOccurrences',