Add a new git::review_cleanup module that implements a CleanupPlan with
prepare() and finish() routines to safely remove/clean tracking and local
branches after a PR/MR is merged. The cleanup logic validates branch names,
ensures a clean worktree, checks remotes/URLs, verifies commits/ancestry,
protects against concurrent worktrees or divergent local/remote commits, and
performs authenticated fetch/push and ref updates. Unit tests for the cleanup
behavior are included.
Wire provider-side cleanup into integrations:
- add an integrations/cleanup module to read provider PR payloads and derive
cleanup inputs
- run cleanup::prepare(...) before performing a merge when an optional
cleanup_path is provided
- after a successful provider merge, run cleanup::finish(...); any failure is
reported as MERGE_ACCEPTED_CLEANUP_FAILED
Also:
- export the new git review_cleanup module (src-tauri/src/git.rs)
- accept an optional cleanup_path parameter in run_integration_review_action
- remove the previous REVIEW_REQUEST_TIMEOUT wrapper around the spawned
blocking task (the integration action is no longer wrapped with the 35s timeout)
