feat(web): align the web UI with the design prototype

- Ambient background in the app shell: three drifting blurred blobs,
  the third one tinted with the current track's cover; can be turned off
  in settings and stays still with reduced motion.
- Island player variant (floating glass panel) next to the bar, chosen
  in settings; player source line ("Album · …", "My Wave"), reactions
  around the transport controls, queue drawer.
- Sidebar: like / dislike counters, pending uploads badge on Queue,
  admin Settings page holding the upload queue limits.
- Collection: header tile with kicker, underline tabs, time / number
  lead column with an equalizer for the current track, album column,
  dimmed dislikes with undo, Play all / Shuffle pills.
- Album: cover-tinted header and Play / Shuffle; artist: artist wave,
  Play and popular tracks (new GET /artists/{id}/top-tracks).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/player/player.ts

@@ -164,18 +164,20 @@ export class Player {
   // --- «Моя волна» ---
 
   /** Запустить волну (или перезапустить с новым контекстом). */
-  async startWave(activity: string | null, mood: string | null) {
+  async startWave(activity: string | null, mood: string | null, seed?: { type: 'artist' | 'album' | 'track'; id: string; label: string }) {
     this.finishAttempt('skip');
     this.leaveWave();
     const res = unwrap(
-      await this.session.client.POST('/api/v1/wave/sessions', { body: { activity, mood } }),
+      await this.session.client.POST('/api/v1/wave/sessions', {
+        body: { activity, mood, ...(seed ? { seed: { type: seed.type, id: seed.id } } : {}) },
+      }),
     );
     const tracks = res.tracks.filter((t) => t.available && t.stream_url);
     if (!tracks.length) {
       this.update({ error: 'wave.empty' });
       return;
     }
-    this.context = { type: 'wave', id: res.session_id };
+    this.context = { type: 'wave', id: res.session_id, label: seed?.label };
     this.queue.shuffle = false;
     this.queue.repeat = 'off';
     this.queue.set(tracks, 0);