feat(cli): record browser agent video

[icycodes]

Summary

• Added support for recording browser agent sessions to MP4 video files in the CLI.
• Introduced fluent-ffmpeg for video conversion from MJPEG frames.
• Implemented real-time MJPEG stream processing via WebSocket in the browser agent subtask.

Test plan

• Run Pochi and use the browser agent.
• Verify that a .mp4 file is generated in the specified directory.
• Check if the video correctly captures the browser session steps.

🤖 Generated with Pochi | Task

[codecov-commenter]

Codecov Report

❌ Patch coverage is 5.85586% with 209 lines in your changes missing coverage. Please review.
✅ Project coverage is 18.11%. Comparing base (5e5a10f) to head (d7f873a).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
packages/cli/src/lib/ffmpeg-mjpeg-to-mp4.ts	5.30%	125 Missing ⚠️
packages/cli/src/tools/new-task.ts	8.95%	61 Missing ⚠️
...ckages/common/src/browser/browser-session-store.ts	0.00%	12 Missing ⚠️
packages/cli/src/cli.ts	0.00%	10 Missing ⚠️
packages/cli/src/task-runner.ts	0.00%	1 Missing ⚠️

❌ Your patch status has failed because the patch coverage (5.85%) is below the target coverage (75.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1337      +/-   ##
==========================================
+ Coverage   13.94%   18.11%   +4.17%     
==========================================
  Files         683      687       +4     
  Lines       62913    63582     +669     
  Branches     1748     1483     -265     
==========================================
+ Hits         8774    11520    +2746     
+ Misses      53858    51787    -2071     
+ Partials      281      275       -6     

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[Copilot]

Pull request overview

This PR adds CLI-side support for recording browser-agent sessions by consuming the browser agent’s WebSocket MJPEG frame stream and converting it into an MP4 via fluent-ffmpeg.

Changes:

• Extend browser session registration to optionally enable a local WebSocket stream outside VSCode.
• Add an MJPEG→MP4 converter module using fluent-ffmpeg, and wire recording/finalization into the newTask tool.
• Introduce new CLI plumbing (blob store in tool options, --ffmpeg flag) and add required dependencies.

Reviewed changes

Copilot reviewed 8 out of 9 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
packages/common/src/browser/browser-session-store.ts	Allows enabling browser stream when not in VSCode; stream URL handling updated.
packages/cli/src/types.ts	Adds blobStore to ToolCallOptions so tools can persist generated binaries.
packages/cli/src/tools/new-task.ts	Connects to the browser stream, collects frames, converts to MP4, and stores a URL reference in the task file system.
packages/cli/src/tools/tests/background-job-integration.test.ts	Updates test setup to provide blobStore in tool options.
packages/cli/src/task-runner.ts	Passes blobStore into tool call options.
packages/cli/src/lib/ffmpeg-mjpeg-to-mp4.ts	New converter implementation based on ffmpeg stdin MJPEG piping and timestamp-based frame repetition.
packages/cli/src/cli.ts	Adds --ffmpeg <path> option to configure ffmpeg binary location.
packages/cli/package.json	Adds ffmpeg + websocket dependencies required for recording.
bun.lock	Locks newly added dependencies (including fluent-ffmpeg transitive deps).

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