feat(artist-detail): user-configurable visibility and order of page sections (closes #252) (#254)

Per bcorporaal's request in #252: album-oriented listeners want a
cleaner artist page focused on the album grid, with the freedom to
reorder/hide bio, top tracks, and similar artists.

Five sections are now reorder- and toggle-able from Settings →
Personalisation → "Artist page sections": Bio, Top tracks, Similar
artists, Albums, Also featured on. The fixed header block (artist
photo, name, action buttons) stays at the top.

Implementation reuses the existing sidebar customizer pattern:

- new `src/store/artistLayoutStore.ts` modelled on `sidebarStore.ts`
  with the same persist + onRehydrateStorage migration so future-added
  sections don't silently disappear from existing users' configs.
- `ArtistDetail.tsx` render block refactored from a flat sequence of
  conditional JSX into a `renderableSectionIds.map()` driven by the
  store. The "first rendered section gets marginTop: 0" rule now
  works regardless of the configured order — both hidden-by-toggle
  and empty-data sections are filtered before the layout decides
  what's first.
- `ArtistLayoutCustomizer` component in Settings, lifted from
  `LyricsSourcesCustomizer` (drag via `useDragSource` + `psy-drop`
  event, per-row toggle, reset button).
- 7 new i18n keys per locale across all 8 languages.

The store hook MUST stay above the loading / !artist early returns —
otherwise React's hook call order mismatches between renders and the
component fails silently. Lesson learned during the refactor.

Co-authored-by: Psychotoxical <dev@psysonic.app>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/locales/zh.ts

@@ -641,6 +641,14 @@ export const zhTranslation = {
     homeCustomizerTitle: '首页',
     sidebarTitle: '侧边栏',
     sidebarReset: '重置为默认',
+    artistLayoutTitle: '艺术家页面板块',
+    artistLayoutDesc: '拖动以重新排序，切换以隐藏艺术家页面的各个板块。没有数据的板块会自动跳过。',
+    artistLayoutReset: '重置为默认',
+    artistLayoutBio: '艺术家简介',
+    artistLayoutTopTracks: '热门曲目',
+    artistLayoutSimilar: '相似艺术家',
+    artistLayoutAlbums: '专辑',
+    artistLayoutFeatured: '也参与了',
     sidebarDrag: '拖动以重新排序',
     sidebarFixed: '始终显示',
     randomNavSplitTitle: '拆分混音导航',