fix: bd sync works when on sync branch (GH#519)

When sync.branch is set to the current branch (e.g., main), bd sync
now commits directly instead of failing with a worktree error.

Changes:
- sync.go: Detect when current branch == sync branch and skip worktree
- sync.go: Show appropriate messages for direct-mode commits/pulls
- doctor.go: Change from Error to OK status when on sync branch

The fix allows users to work directly on the sync branch without
having to switch to a different branch for bd sync to work.

Closes: GH#519

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.beads/.gitignore

@@ -30,3 +30,5 @@ beads.right.meta.json
 !issues.jsonl
 !metadata.json
 !config.json
+deletions.jsonl
+deletions.jsonl.migrated