Data-loss fixes in syncWorktreeToHead:
- Untracked-restore checks `git ls-tree -r --name-only HEAD` to skip
paths the new tip added as tracked files; user bytes stay in the
stage dir instead of clobbering merged content.
- Apply-failure on a deleted/renamed file: conflictedFiles falls back
to parsing `diff --git a/<p> b/<p>` headers when --diff-filter=U
returns nothing.
- All git invocations pass `-c core.quotePath=false` so non-ASCII
paths round-trip through copyFileSync.
- Stash-and-ff re-verifies rev-parse HEAD === newSha right before
each `reset --hard HEAD` (TOCTOU). On mismatch we bail with patch
preserved on disk.
- Stage dir lifecycle moved into try/finally with preserveStageDir
flag — kept whenever the user's edits live only in patchPath; rm'd
on all clean exits.
- Patch written to disk before the apply attempt, not only on
failure, so a crash between snapshot and apply doesn't lose edits.
Multi-worktree-same-branch fix:
- New getRegisteredWorktreeBranches returns Array<{branch,path}>
instead of collapsing into a Map. Multiple worktrees can share a
branch via `git worktree add --force -b`; merger now syncs all of
them rather than silently skipping all but the last.
Contract + surfacing fixes:
- JSDoc on merge:auto-sync GitMutationType now lists the actually-
emitted outcome strings + stage enum.
- GET /api/tasks/merge-advance-events joins merge:auto-sync events
within ±5min of the advance and returns them in a new
`autoSync: AutoSyncOutcome[]` field; useMergeAdvanceNotice exposes
the same shape so the banner can surface pop-conflicts (including
patchPath) instead of dropping them.
Hygiene:
- Merger now reads the setting via normalizeMergeAdvanceAutoSyncMode
instead of an inline check + `as unknown` cast.
New tests:
- Untracked-collides-with-tracked preserves merged content.
- Apply failure on deleted file populates conflictedFiles from
patch header.
- Route surfaces autoSync outcomes (clean-sync + pop-conflict)
joined within the time window.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>