Feature Request: Selective per-file accept/revert for Copilot CLI agent changes like `git add -p`

[abhinavkaurav]

Describe the feature or problem you'd like to solve

After Copilot CLI applies file changes in a turn, the only recovery option is /rewind which reverts everything in that turn. There is no way to selectively keep some file changes while discarding others.

Proposed solution

1. post-apply interactive review: After a turn completes, offer a /review-changes command that lists modified files and lets you revert selected ones
2. /rewind --file <path>: Extend /rewind to accept a file path argument
3. Plan mode enhancement: In plan mode, show actual code diffs (not just natural language descriptions) before execution, with per-file approval
4. VS Code /ide integration: When connected via /ide, route file-level accept/discard through VS Code's native diff editor

Any of these would be a significant improvement over the current all or nothing model

Example prompts or workflows

After a turn applies file changes, users should be able to selectively accept or revert on a per-file basis and ideally per chunk within a file similar to git add -p.

Something like:

Copilot modified 5 files. Review changes?
[1] src/auth.ts - 12 lines changed [keep/revert]
[2] src/config.ts - 4 lines changed [keep/revert]
[3] tests/auth.test.ts - 28 lines changed [keep/revert]

Additional context

Problems

Mechanism	Granularity	Limitation
Write permission prompt	Per write-call	Binary yes/no; one call can touch many files
/diff	Read-only, post-apply	Shows changes but cannot act on them
/rewind	Entire turn	All-or-nothing cannot keep partial changes

/rewind is a blunt instrument - it treats a multi-file turn as atomic. Real-world agent tasks often span several files, and it's common for most changes to be correct while one file went in an unintended direction. Forcing an all-or-nothing revert actively works against iterative, confident use of the agent.