Adds interactive manual conflict resolution for `bd sync --resolve --manual`:
- Shows field-by-field diff between local and remote versions
- Prompts user to choose: local (l), remote (r), merge (m), skip (s)
- Supports viewing full JSON diff with 'd' option
- Skipped conflicts remain in conflict state for later resolution
- Integrates with existing 3-way merge infrastructure
New files:
- cmd/bd/sync_manual.go: Interactive conflict resolution logic
- cmd/bd/sync_manual_test.go: Unit tests for helper functions
Closes hq-ew1mbr.28
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
