Feature: Add --record flag for meeting video recording

[ocean-wave-ai]

Summary

Add a --record flag to openutter join that captures a video recording of the Google Meet session alongside the transcript. This enables tl;dv/Fireflies-style meeting playback.

Motivation

OpenUtter already joins meetings via a headless Playwright browser and captures captions. Since the browser renders the full Meet UI (participant tiles, screen shares, chat), we can leverage Playwright built-in recordVideo to capture the entire session as a video file — no additional dependencies required.

This makes OpenUtter a complete meeting capture tool: transcript + video.

Proposed Implementation

1. New CLI flag: --record on openutter join
2. Playwright recordVideo: Pass recordVideo: { dir: "<recordings-dir>", size: { width: 1280, height: 720 } } to the browser context options
3. Recording saved to: ~/.openclaw/workspace/openutter/recordings/<meeting-id>.webm
4. Optional post-processing: If ffmpeg is available, convert .webm → .mp4 for broader compatibility
5. Channel notification: Send a message when recording is saved (like transcripts do)

CLI Usage

# Record + transcript
npx openutter join https://meet.google.com/abc-defg-hij --auth --record

# Record with duration limit
npx openutter join https://meet.google.com/abc-defg-hij --auth --record --duration 60m

Changes Required

• bin/openutter.mjs — Add --record to help text
• scripts/utter-join.ts — Parse --record flag, configure recordVideo on browser context, handle post-meeting file rename/conversion, send notification

Notes

• Playwright recordVideo captures the browser viewport, so the recording shows whatever the bot sees (grid view of participants, screen shares, etc.)
• WebM is the native format; MP4 conversion is best-effort (requires ffmpeg)
• Recording files can be large (~50-100MB/hour) — users should be aware of disk usage