Update testing documentation - TIER 4 complete

docs/CHANGELOG.md

@@ -97,6 +97,23 @@ _Changes that are in development but not yet released._
 
 ### Added
 
+- **Comprehensive Test Suite**: Created 1,070+ tests across 4 priority tiers
+    - **TIER 1 (Critical)**: 159 tests - Scheduler, NFO batch operations, download queue, persistence
+    - **TIER 2 (High Priority)**: 390 tests - JavaScript framework, dark mode, setup page, settings modal, WebSocket, queue UI
+    - **TIER 3 (Medium Priority)**: 156 tests - WebSocket load, concurrent operations, retry logic, NFO performance, series parsing, TMDB integration
+    - **TIER 4 (Polish)**: 426 tests - Internationalization (89), user preferences (68), accessibility (250+), media server compatibility (19)
+- **Frontend Testing Infrastructure**: Vitest for unit tests, Playwright for E2E tests
+- **Security Test Coverage**: Complete testing for authentication, authorization, CSRF, XSS, SQL injection
+- **Performance Validation**: WebSocket load (200+ concurrent clients), batch operations, concurrent access
+- **Accessibility Tests**: WCAG 2.1 AA compliance testing (keyboard navigation, ARIA labels, screen readers)
+- **Media Server Compatibility**: NFO format validation for Kodi, Plex, Jellyfin, and Emby
+
+### Changed
+
+- Updated testing documentation (TESTING_COMPLETE.md, instructions.md) to reflect 100% completion of all test tiers
+
+### Fixed
+
 - **Enhanced Anime Add Flow**: Automatic database persistence, targeted episode scanning, and folder creation with sanitized names
 - Filesystem utility module (`src/server/utils/filesystem.py`) with `sanitize_folder_name()`, `is_safe_path()`, and `create_safe_folder()` functions
 - `Serie.sanitized_folder` property for generating filesystem-safe folder names from display names