fix: Workflow dashboard blocks input by reloading history on animation ticks

[tt-a1i]

Problem

Opening the Workflow TUI dashboard during a run causes severe keyboard/navigation lag. The dashboard animation timer runs every 120 ms but calls refresh() -> loadRunEntries() on each tick. That loader synchronously reads every persisted workflow and hydrates result/transcript artifacts before filtering by session and request time.

Observed evidence

• Configured local runtime: c8f2c13d49f2e6cd3b389dfff72ccc2eaca970c1.
• The live Pi process reached approximately 101% CPU. A macOS sample captured the main thread inside a timer callback, with string processing, JSON parsing, file opens and GC; JavaScript function names were not available in that sample.
• Calling the real loadRunEntries(new Map(), "diagnostic-no-session", new Set(), Date.now()) against approximately 13 MB of local history returned zero entries but took 3522, 3327 and 3952 ms under Node. Bun measurements were 3764, 2138 and 1942 ms. These are exploratory local measurements under concurrent load, not a formal benchmark.
• The reported run had eight children. Raw sessions, transcripts and screenshots are private local evidence and are not attached.

Expected behavior / acceptance

• Animation ticks and keyboard navigation must not repeatedly scan or hydrate historical artifacts.
• Filter unrelated runs before expensive normalization/hydration; load transcript artifacts only when the user opens the corresponding detail.
• Preserve live updates, terminal transitions, historical navigation and canonical recovery semantics.
• Add deterministic regression coverage for filesystem work on animation ticks and lazy artifact loading.
• Run bun run check, bun run test, and repeat the local read-only timing probe.

The separate ordinary conversation view may have additional performance costs; this issue targets the reproduced dashboard path.

[tt-a1i]

Fix prepared in #422 at 38e4869a4bb81c84b63cf03ff72704d486d59b80.

Canonical investigation: Workflow dashboard refresh.

The baseline fails the new regression tests: ten animation ticks plus return navigation perform eleven history reads, and the overview loads two side artifacts. Fixed steady animation/navigation performs zero history reads/scans; canonical settlement is read once and historical transcripts load on demand.

Validation: dashboard 27 passed; bun run check passed; full Node suite 1430 passed / 1 skipped; Vitest 30 passed. Required GitHub CI is running. Real-terminal acceptance after reload and release publication remain unverified.

[tt-a1i]

All three required CI checks passed for 38e4869a4bb81c84b63cf03ff72704d486d59b80: run 34044897538. PR #422 remains open with REVIEW_REQUIRED; main requires one independent approval after the last push. The repository does not allow auto-merge. The fix is not yet merged or loaded into the running Pi session.