- Remove author insights and duplicate suggestions panels, composables, DTOs, and all backend support
- Add genre and tag duplicate detection, merge, and dismiss with server-side paginated scan results
- Consolidate per-entity-type tools into a single entity-manager module backed by the Strategy pattern
- Support browse, merge, rename, delete, split, and dismiss across all entity types (author, genre, tag, narrator, publisher, language, series)
- Replace old tools module with unified entity-manager controller, service, and repository; add 85+ unit tests