refactor(web): delete unmounted components carrying real logic (TASK-2632)

[xarmian]

Closes TASK-2632.

A one-shot dead-code sweep. Two dead components had been found incidentally in one week, each discovered only because someone was about to change behaviour it appeared to depend on — VersionHistory during BUG-2608 (its apparent liveness would have blocked a default history limit), and EditorToolbar before it. One is an oddity; two is a pattern.

Instrument

Two passes over all 110 components under web/src/lib/components:

1. Plain substring grep of each basename across web/src + web/e2e → 4 zero-hit. This pass counts comments as liveness, so it under-reports deadness — conservative in the safe direction.
2. Import/mount-only regex (a from-import of the .svelte path, a dynamic import() of it, or a <Name element) → 6 zero-hit. The two extras were exactly the comment-shadowed cases pass 1 could not see.

Controls. A known-live component (BacklinksPanel) resolves to its single consumer under both passes. Each of the six candidates then took a repo-wide plain grep with no include filters and no scope beyond node_modules/.git/.svelte-kit/build, and every surviving hit was read individually. Pass 2's one known blind spot — a component referenced only by vi.mock(path) — was checked by enumerating every vi.mock target ending in .svelte; all are .svelte.ts store/service modules except CommentEditor, which is independently imported. None of the six is in that set.

Deleted (6 dead + 2 cascade orphans)

File	Why it is dead
activity/ActivityFeed.svelte	A live /activity route page and TimelineActivityCard both exist; neither touches it.
charts/LineChart.svelte	From the TASK-1632 LayerCake library; only BarChart reached the insights pages.
charts/layers/Lines.svelte	Cascade — exactly one consumer, LineChart. AxisX/AxisY stay: shared with BarChart.
charts/Sparkline.svelte	TASK-1638. Its only repo-wide reference was a prose comment recording that PLAN-1542 chose not to show it. Zero mounts.
editor/MermaidRenderer.svelte	Superseded by the MermaidCodeBlock NodeView in Editor.svelte, which owns the render queue, toggle and error state.
versions/VersionHistory.svelte	The BUG-2608 find (620 lines). The live path is ItemTimeline → TimelineVersionCard → DiffView; DiffView stays.
attachments/fixtures/LightboxStub.svelte	Its last consumer was removed by the TASK-2489 atomic cutover — orphaned, not born dead.
attachments/fixtures/lightboxStub.ts	Cascade — the stub's recording surface; the pair referenced only each other.

Nothing was reclassified live-but-obscure, so no import-site comments were owed.

Docs

Two edits so no artifact points at a deleted file: the web/README.md component tree drops the activity/ line, and the UserOverviewTab comment now says the Sparkline component was deleted here and is recoverable from history — otherwise a future reader greping that decision record finds nothing.

Gates

• npx vite build — exit 0
• make lint — 0 issues
• go test ./... — exit 0, 25 packages ok
• make test-pg — not applicable: zero Go files and zero store SQL in the diff
• npm run check — 0 errors, 6 warnings (all pre-existing, in files this diff does not touch)
• npm run test — 95 files, 1706 tests passed
• Codex CLI — CLEAN on round 1, with independent verification of vi.mock / dynamic imports / component registries / Go embeds / Playwright + build config / JSON / Markdown / generated web/build

Git history is the archive; anything worth resurrecting is one revert away.

https://claude.ai/code/session_017jD6t1zjxGSq47SQpZfp1V