- Added validatePreExport to prevent data loss
- Added checkDuplicateIDs to detect corruption
- Added checkOrphanedDeps to find orphaned dependencies (both sides)
- Added validatePostImport to ensure imports don't lose data
- CRITICAL FIX: Removed post-pull export that clobbered fresh JSONL
- Conservative checks when JSONL is unreadable
- Efficient COUNT(*) SQL path instead of loading all issues
- Comprehensive test coverage including edge cases