v0.6.4 — 0.6.x Bug-Crush & Capture Trust

Closes out the 0.6.x line — the v0.6.3 bug-crush and the v0.6.4 capture-trust work, shipped together.

🎙️ Capture reliability (v0.6.4)

• Verified auto-heal after audio route changes — a recording is trusted as "resumed" only once real audio actually starts flowing again. Fixes a bug where a route change (e.g. connecting AirPods) could leave the remote side silently recording as silence.
• A system-audio failure never stops your microphone — if the system stream can't recover, you get a clear "remote audio couldn't be recovered — only your mic is recording" notice, and your recording keeps going.
• Long recordings no longer lock out after a transient audio glitch.
• Per-session diagnostics no longer leak route-change/anomaly counts between recordings.

📝 Transcript quality

• No more Local Local Speaker double labels; multi-chunk transcripts are always in correct time order.
• More robust echo removal across crash-recovered recordings.

💾 Archival

• No-mic / system-audio-only recordings now always compress to .m4a — no leftover raw .wav files (the WAV is kept only if compression genuinely fails).
• Concatenation can no longer hang on a corrupt audio file.

🧠 Summaries

• Summaries are dated to when you recorded, not when you generated them.
• Rate-limit retries (OpenAI 429/503) and better LM Studio context handling.
• Settings now persists all summary options.

🔒 Privacy & integrity

• Speaker names, file paths, and meeting/session titles are redacted (<private>) in system logs.
• Missing/corrupt model files are surfaced to you (launch notification + a Settings indicator), and all problems are reported at once.

✨ Polish

• About section with version + build number; software version stamped into every transcript.
• Several crash-safety and thread-safety hardenings.

⚠️ Known limitation

• iPhone cellular calls answered on the Mac (Continuity) still aren't captured on the remote side — ScreenCaptureKit structurally can't see telephony audio. A Core Audio tap is coming in v0.7.0 to fix this. Until then, use headphones to avoid the remote bleeding into your mic.

Full history: v0.6.2…v0.6.4 — v0.6.2...v0.6.4