SubMiner/backlog/tasks/task-23 - Add-opt-in-JLPT-level-tagging-by-bundling-and-querying-local-Yomitan-dictionary.md

id, title, status, assignee, created_date, labels, dependencies, priority

id	title	status	assignee	created_date	labels	dependencies	priority
TASK-23	Add opt-in JLPT level tagging by bundling and querying local Yomitan dictionary	In Progress		2026-02-13 16:42			high

Description

Implement an opt-in JLPT token annotation feature that annotates subtitle words with JLPT level in-session. The feature should use a bundled dictionary source from the existing JLPT Yomitan extension, parse/query its dictionary file to determine whether a token appears and its JLPT level, and render token-level visual tags as a colored underline spanning each token length. Colors must correspond to JLPT levels (e.g., N5/N4/N3/N2/N1) using a consistent mapping.

Acceptance Criteria

• #1 Add an opt-in setting/feature flag so JLPT tagging is disabled by default and can be enabled per user/session as requested.
• #2 Bundle the existing JLPT Yomitan extension package/data into the project so lookups can be performed offline from local files.
• #3 Implement token-level dictionary lookup against the bundled JLPT dictionary file to determine presence and JLPT level for words in subtitle lines.
• #4 Render a colored underline under each token determined to have a JLPT level; the underline must match token width/length and not affect layout or disrupt line rendering.
• #5 Assign different underline colors per JLPT level (at minimum N5/N4/N3/N2/N1) with a stable mapping documented in task notes.
• #6 Handle unknown/no-match tokens as non-tagged while preserving existing subtitle styling and interaction behavior.
• #7 When disabled, no JLPT lookups are performed and subtitles render exactly as current behavior.
• #8 Add tests or deterministic checks covering at least one positive match, one non-match, and one unknown/unsupported-level fallback path.
• #9 Document expected dictionary source and any size/performance impact of bundling the JLPT extension data.
• #10 If dictionary format/version constraints block exact level extraction, the task includes explicit limitation notes and a deterministic fallback strategy.

Definition of Done

• #1 Feature has a clear toggle and persistence of preference if applicable.
• #2 JLPT rendering is visually verified for all supported levels with distinct colors and no overlap/regression in subtitle legibility.

Note

• Full performance/limits documentation and dictionary source/version/perf notes are deferred and tracked separately.