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/widgets/AppShell.module.css

@@ -1,4 +1,5 @@
 .shell {
+  position: relative;
   display: grid;
   grid-template-columns: 240px 1fr;
   grid-template-rows: 60px 1fr 88px;
@@ -9,6 +10,23 @@
   height: 100%;
 }
 
+.shell > :where(:not([aria-hidden])) {
+  position: relative;
+  z-index: 1;
+}
+
+/* Плеер-остров: плавает над контентом, контенту — запас снизу (docs/design.md#4). */
+.island {
+  grid-template-rows: 60px 1fr;
+  grid-template-areas:
+    'top top'
+    'side content';
+}
+
+.island .content {
+  padding-bottom: 132px;
+}
+
 .top {
   grid-area: top;
   display: flex;
@@ -118,6 +136,33 @@
   color: var(--text3);
 }
 
+.navLabel {
+  flex: 1;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.navCount {
+  font-size: 12px;
+  color: var(--text3);
+  font-variant-numeric: tabular-nums;
+}
+
+.navBadge {
+  min-width: 20px;
+  height: 20px;
+  padding: 0 6px;
+  border-radius: var(--radius-pill);
+  background: var(--accent);
+  color: #fff;
+  font-size: 11px;
+  font-weight: 700;
+  line-height: 20px;
+  text-align: center;
+}
+
 .navItem[data-status='active'] .navIcon {
   color: var(--accent2);
 }
@@ -140,6 +185,12 @@
     font-size: 0;
   }
 
+  .navLabel,
+  .navCount,
+  .navBadge {
+    display: none;
+  }
+
   .navSection {
     margin: 14px 0 6px;
     text-align: center;