Add 20 integration tests covering all comment indexing scenarios: Core operations: - Create comment (normal, idempotent, out-of-order) - Update comment (content, metadata) - Delete comment (soft delete) Threading: - Root/parent references - Reply count updates - Thread hierarchy queries Security: - Invalid DID rejection - Content length limits - Malformed AT-URI rejection - Threading immutability (reject mutation attempts) Out-of-order handling: - Child arrives before parent (count reconciliation) - Multiple children before parent Resurrection: - Recreate deleted comment (same parent) - Recreate deleted comment (different parent - tests threading ref updates) Repository queries: - ListByRoot, ListByParent, ListByCommenter - Soft delete filtering All tests verify both database state and denormalized counts. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>