refactor: remove Edit Metadata right-click option
Removes the Edit Metadata feature from the anime context menu and
deletes all related backend/frontend code:
Backend:
- DELETE PUT /api/anime/{anime_key} endpoint
- DELETE AnimeMetadataUpdate model and KEY_PATTERN regex
- DELETE MAX_INPUT_LENGTH constant
Frontend:
- DELETE edit-modal.js component
- DELETE edit metadata modal HTML from index.html
- DELETE edit-modal.js script tag
- DELETE edit-only CSS (.edit-modal-content, .edit-section,
.field-error, .input-error, .key-warning, .info-grid,
.info-item, .input-with-action, .btn-fetch-tmdb, .tmdb-*)
- REMOVE 'Edit Metadata' item from context menu (NFO Diagnostics
preserved)
Tests:
- DELETE test_anime_edit_endpoints.py
- DELETE test_edit_modal.py
- DELETE test_anime_key_rename.py