Pin Home meeting artifact row targets

[r3dbars]

Summary

• Add a small Home meeting row target helper so transcript/audio Finder actions resolve through one tested path.
• Route saved and failed meeting reveal actions through that helper, while keeping retranscribe gated on retained audio that has a real Finder target.
• Add deterministic fast coverage for exact transcript/audio reveal targets and failed-audio visibility vs retry readiness.

Validation

• scripts/dev/agent-preflight.sh
• bash -n run-tests.sh
• bash -n scripts/entrypoints/run-tests.sh
• bash build-deps.sh --force (needed because build guard reported missing/stale deps)
• bash build.sh --no-open
• bash run-tests.sh --filter RecentCaptureScanners
• bash run-tests.sh --filter FailedMeetingPresentation
• bash run-tests.sh --filter UIAutomationSurfaceContract
• bash run-tests.sh (5304/5304 passed)

Review

• codex review --base origin/main was attempted, but local Codex usage was exhausted before a verdict.
• Fallback independent review: Claude Code 2.1.157 reviewed the branch diff. It found only P3/low notes; the retranscribe/audio-target guard note was addressed before final validation. Remaining low note: audio reveal intentionally selects the first retained audio URL, preserving existing behavior.

Notes

• PR Fix Home dashboard row actions, hover reveal, and stats focus ring #1110 already covers the Home menu target/hover/focus fix path, so this PR does not duplicate that patch.
• Existing package coverage already proves replacement retranscription keeps the original URL/date and does not create duplicate Markdown rows.