feat(library): "favorites only" filter on Albums, Artists, AdvancedSearch (#466)

* feat(ui): StarFilterButton component + common i18n keys

Reusable toggle button for "favorites only" filtering. Three size
variants for different toolbar contexts:
- default: icon + label (Albums-style)
- compact: icon-only with 0.5rem padding (Artists view-mode buttons)
- small:   icon + label at 12px / 4×14 padding (AdvancedSearch tabs)

Adds common.favorites + favoritesTooltipOff/On in all 8 locales.

* feat(library): "favorites only" filter on Albums, Artists, AdvancedSearch

Client-side filter using the existing useMemo pipelines on each page.
Reads starred state from item.starred + playerStore.starredOverrides
(O(1) Map lookup, picks up live star toggles without refetch).

- Albums: toolbar button (default size) next to compilation filter.
- Artists: toolbar button (compact / icon-only) before the Images toggle.
- AdvancedSearch: toolbar button (small) next to the result-type tabs;
  filters all three result categories (artists / albums / songs) and
  updates the count badges accordingly.

Filter state is ephemeral per-page (not persisted) so users don't get
surprised by hidden items after a restart. Zero extra server calls.

* docs(contributors): credit + changelog entry for #466

src/locales/zh.ts

@@ -488,6 +488,9 @@ export const zhTranslation = {
     filterSearchGenres: '搜索流派…',
     filterNoGenres: '未找到匹配流派',
     filterClear: '清除',
+    favorites: '收藏',
+    favoritesTooltipOff: '仅显示收藏',
+    favoritesTooltipOn: '显示全部',
     play: '播放',
     bulkSelected: '已选 {{count}} 首',
     clearSelection: '清除选择',