feat(web): My Wave button, mood picker and endless wave playback (M4)

- WaveButton: TypeScript port of the prototype's canvas animation
  (orb and liquid), breathing at rest, pulsing to the track's BPM and
  energy in the cover palette, following the cursor, pressing with a
  spring; reduced motion and hidden tabs slow or stop it
- home: the wave in the centre with activity and mood chips; changing
  them while playing rebuilds the upcoming tracks without stopping
- player wave mode: asks for the next batch when two tracks are left,
  sends complete / skip / early skip / like / dislike as feedback and
  refreshes the queue right after a reaction or an early skip
- tracks expose bpm, energy and loudness once analysed; library page
  shows analysis progress and 7-day wave metrics; wave style setting

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

apps/web/src/pages/home.module.css

@@ -4,60 +4,94 @@
   flex-direction: column;
   align-items: center;
   justify-content: center;
-  gap: 24px;
+  gap: 28px;
+  padding: 24px 0;
   text-align: center;
 }
 
-.greeting {
-  margin: 0;
+.orbLabel {
+  margin-top: 4px;
   font-family: var(--font-display);
-  font-size: 24px;
+  font-size: 22px;
   font-weight: 600;
   letter-spacing: -0.01em;
+  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.35);
 }
 
-.orb {
+.orbContext {
+  font-size: 13px;
+  opacity: 0.85;
+}
+
+.note {
+  margin: -12px 0 0;
+  color: var(--text2);
+  font-size: 13px;
+}
+
+.picker {
+  display: flex;
+  flex-direction: column;
+  gap: 18px;
+  max-width: 720px;
+}
+
+.group {
   display: flex;
   flex-direction: column;
   align-items: center;
-  justify-content: center;
-  gap: 6px;
-  width: 300px;
-  height: 300px;
-  max-width: 70vw;
-  max-height: 70vw;
-  border-radius: 50%;
-  color: #fff;
-  background:
-    radial-gradient(circle at 35% 30%, rgba(156, 198, 255, 0.55), transparent 45%),
-    radial-gradient(circle at 65% 70%, var(--wave-color3), transparent 55%),
-    radial-gradient(circle at 50% 50%, var(--wave-color2), var(--wave-color1) 70%);
-  box-shadow: 0 0 80px rgba(47, 128, 255, 0.35);
-  opacity: 0.85;
-  animation: breathe 6s ease-in-out infinite;
+  gap: 10px;
 }
 
-.orbLabel {
-  font-family: var(--font-display);
-  font-size: 18px;
-  font-weight: 600;
-}
-
-@keyframes breathe {
-  50% {
-    transform: scale(1.03);
-  }
-}
-
-@media (prefers-reduced-motion: reduce) {
-  .orb {
-    animation: none;
-  }
-}
-
-.soon {
-  max-width: 420px;
+.groupTitle {
   margin: 0;
+  font-size: 11px;
+  font-weight: 700;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  color: var(--text3);
+}
+
+.chips {
+  display: flex;
+  flex-wrap: wrap;
+  justify-content: center;
+  gap: 8px;
+}
+
+.chip {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  height: 38px;
+  padding: 0 16px;
+  border-radius: var(--radius-pill);
+  border: 1px solid var(--line);
+  background: var(--surface2);
+  color: var(--text);
+  font-size: 14px;
+  font-weight: 500;
+  transition:
+    background 0.15s,
+    box-shadow 0.15s;
+}
+
+.chip > span {
   color: var(--text2);
-  line-height: 1.5;
+}
+
+.chip:hover {
+  background: var(--surface3);
+}
+
+.chipOn,
+.chipOn:hover {
+  background: var(--accent);
+  border-color: var(--accent);
+  color: #fff;
+  box-shadow: var(--glow);
+}
+
+.chipOn > span {
+  color: #fff;
 }