(MOT-3874) feat(shell): coder::apply-patch + worktree add/remove

[ytallo]

Adds the apply_patch (V4A) format codex-family models are trained on:
*** Begin/End Patch with Add/Delete/Update File hunks, @@ context
markers, optional Move to, and End of File pinning. seek_sequence and
the replacement engine are ported from OpenAI's codex-rs apply-patch
crate (Apache-2.0) so context matching (exact -> rstrip -> trim ->
unicode-normalised) matches the reference; the parser is a compact
re-implementation pinned by the reference test cases.

All-or-nothing: every hunk resolves through the jail and computes
before anything is written (context mismatch fails C210 with re-read
guidance, filesystem untouched); writes land atomically per file and
modified files return a bounded echo of the first changed region.

Refs MOT-3874

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 9e4bfa2a-8510-4ffc-8126-6de1fb896a8a

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/coder-apply-patch

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
workers	Ready	Preview, Comment	Jul 6, 2026 11:41am
workers-tech-spec	Ready	Preview, Comment	Jul 6, 2026 11:41am

[github-actions]

skill-check — worker

0 verified, 32 skipped (no docs/).

Layer	Result
structure	✓
vale	✓
ai	✓
render	✓

Four for four. Nicely done.

[ytallo]

Consolidated into #423.