feat(core/frontend): wire settings/avatar/image-gen + real data render (library/product-detail/pipeline)

App.tsx: thread saveProfile/changePassword/uploadAvatar/generateImages handlers + assets prop to pages.
- settings.tsx: profile save / password modal / avatar upload wired; notification/theme prefs -> localStorage
- library.tsx + product-detail: asset thumbnails + grids render real TOS preview_url
- ai-tools ImageWorkbenchPage: 生成图片 wired to /api/ai/generate-image, renders returned assets
- pipeline.tsx stage2-5: base_assets/storyboard/video_segments(adopted_asset)/timeline(clips/subtitles/bgm)
  rendered from real project data; graceful empty states
- types.ts: +VideoSegment.adopted_asset, +Timeline.subtitle_tracks/bgm_tracks
verified: tsc --noEmit clean; screenshots confirm pipeline stages 2-5 + product-detail render real data+images
(demo asset object_keys re-pointed to image objects so thumbnails resolve)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

core/frontend/src/product-detail-page.css

@@ -698,6 +698,8 @@
     position: relative;
     overflow: hidden;
   }
+  /* 有 preview_url 显真图:铺满缩图、cover 裁切、继承圆角 */
+  .asset-card .thumb img { width: 100%; height: 100%; object-fit: cover; display: block; border-radius: inherit; }
   .asset-card .thumb .type-pill {
     position: absolute; top: 8px; left: 8px;
     padding: 3px 8px;