Add comprehensive implementation planning documents for two features:
SSR_BOOKSHELF_IMPLEMENTATION.md:
- Complete SSR-first bookshelf page implementation plan
- Server-side rendering of books and saved filters
- Template changes with pagination controls
- Client-side TypeScript refactor (remove async x-init)
- Testing plan with performance benchmarks
- Rollback procedures and potential issues
- 803 lines covering full implementation lifecycle
GET_SAVED_FILTER_BY_ID_IMPLEMENTATION.md:
- Plan for GET /api/saved-filters/:id endpoint
- Reuses existing GetSavedFilterByID database query
- Handler and service layer implementation
- Integration tests covering all contexts (no auth, user, different users)
- Bruno API collection YAML file
- API documentation updates
- Security considerations (404 for cross-user access)
- Future enhancements (caching, batch operations)
Both documents follow PROJECT_GUIDELINES.md patterns:
- Service layer architecture
- Test helpers usage
- Bruno YAML documentation
- Comprehensive testing plans
- Rollback procedures
Stored in git history for future reference and implementation.
