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/ai-tools-page.css

@@ -486,6 +486,14 @@
   cursor: pointer;
 }
 .image-workbench .gen-image .placeholder { position: absolute; inset: 0; }
+/* 生成结果真图 · 填满 .gen-image(比例由容器 aspect-ratio 控制) */
+.image-workbench .gen-image-img {
+  position: absolute; inset: 0;
+  width: 100%; height: 100%;
+  object-fit: cover;
+  display: block;
+  background: var(--black-alpha-4);
+}
 /* 右上浮层按钮组(§4.18 .gen-image-actions) */
 .image-workbench .gen-image-actions {
   position: absolute; top: 8px; right: 8px;