SubMiner/backlog/tasks/task-182.1 - Remove-misleading-session-new-word-metric-from-session-detail-chart.md

id, title, status, assignee, created_date, updated_date, labels, milestone, dependencies, references, parent_task_id, ordinal

id	title	status	assignee	created_date	updated_date	labels	milestone	dependencies	references	parent_task_id	ordinal
TASK-182.1	Remove misleading session new-word metric from session detail chart	Done	@codex	2026-03-18 01:41	2026-03-18 05:28	bug stats ui	m-1		/Users/sudacode/projects/japanese/SubMiner/stats/src/components/sessions/SessionDetail.tsx /Users/sudacode/projects/japanese/SubMiner/stats/src/components/sessions/SessionsTab.tsx /Users/sudacode/projects/japanese/SubMiner/stats/src/lib/media-session-list.test.tsx	TASK-182	101500

Description

Remove the misleading New words series from the session detail chart so the stats UI no longer presents a fabricated metric that mirrors total words. Keep the session chart focused on the real cumulative totals already backed by tracker data.

Acceptance Criteria

• #1 Expanded session detail chart no longer renders or labels a New words metric in the graph, tooltip, or legend
• #2 Session detail still renders total-word and known-word series correctly after the metric removal
• #3 Automated frontend coverage prevents the New words label from reappearing in expanded session detail

Implementation Plan

1. Add a focused stats frontend regression test that renders expanded session detail and asserts the misleading New words label is absent while Total words remains.
2. Remove the fabricated New words area series, tooltip mapping, legend chip, and now-unused left-axis chart plumbing from stats/src/components/sessions/SessionDetail.tsx.
3. Add a user-visible changelog fragment describing the session chart cleanup.
4. Run targeted frontend tests plus cheap verification and record any blockers.

Implementation Notes

Added a focused server-render regression test for SessionDetail copy to ensure the misleading New words label stays removed.

Removed the fabricated New words chart series and its legend/tooltip plumbing from the expanded session detail view.

Verification: bun test stats/src/lib/session-detail.test.tsx stats/src/lib/media-session-list.test.tsx passed. bash .agents/skills/subminer-change-verification/scripts/verify_subminer_change.sh --lane core stats/src/components/sessions/SessionDetail.tsx stats/src/lib/session-detail.test.tsx changes/2026-03-18-remove-session-new-words-series.md passed and wrote artifacts under .tmp/skill-verification/subminer-verify-20260317-184440-1aMWkM.

Manual spot-check note: bun test stats/src/lib/yomitan-lookup.test.tsx is currently red on a pre-existing AnimeOverviewStats lookup-rate assertion unrelated to this session-detail change.

Final Summary

Removed the misleading New words metric from expanded session charts. Session detail now shows only the real total-word and known-word lines, backed by existing tracker data, with regression coverage that prevents the New words label from reappearing.