- Add 3-way merge deletion tracking using snapshot files
- Create .beads/beads.base.jsonl and .beads/beads.left.jsonl snapshots
- Integrate into both sync.go and daemon_sync.go
- Add comprehensive test suite in deletion_tracking_test.go
- Update .gitignore to exclude snapshot files
This fixes the resurrection bug where deleted issues come back after
multi-workspace git sync. Uses the beads-merge 3-way merge logic to
detect and apply deletions correctly.
708a81c491