Add Show Audio in Finder to the meeting note menu
Summary
Intent: A meeting note with a local recording had no way to jump to the audio file on disk from the note itself. This adds Show Audio in Finder (Explorer on Windows, Folder on Linux) under Re-transcribe in the note's overflow menu, shown only when the recording exists on this device.
Demo
Verified live in the dev app: opening a recorded note shows the item under Re-transcribe, above Export, and clicking it opens Finder at the session folder containing audio.mp3.
Verification
After resolving the conflict with the export-dialog change at d29625818ac6d9954cbe42e1e8b66554b914fb6f: combined-workspace desktop typecheck and all 4,223 tests passed, including the audio-folder and export-dialog regressions. UI build, desktop lint/i18n, common CI/license checks and branch formatting passed. Offline zizmor reports 337 existing workflow findings. The follow-up at f638dd908f9cb1f4c29c810a38cfa29b6a4f894f removes the separator-count and platform-label-only tests; all 21 remaining overflow tests and formatting passed. Current-head CI/review pending; the manual Finder check above is from the original contribution, not a new packaged-app test.
Summary by cubic
Adds a platform-specific Show Audio in Finder/Explorer/Folder action to the meeting note overflow menu so users can open the session folder containing the local recording. The item appears only when the recording exists on this device and is placed under Re-transcribe, above Export.