feat(most-played): add toggle to filter compilation artists

Toggle button in the Top Artists section header hides known compilation
artist names (Various Artists, VA, Soundtracks, OST, etc.) from the
ranking. Default off. Active state shown in accent color.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/styles/components.css

@@ -6417,12 +6417,37 @@
   margin-bottom: 2.5rem;
 }
 
+.mp-section-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  margin-bottom: 0.75rem;
+}
+
+.mp-filter-btn {
+  display: flex;
+  align-items: center;
+  gap: 5px;
+  font-size: 12px;
+  padding: 4px 10px;
+  opacity: 0.6;
+}
+
+.mp-filter-btn:hover { opacity: 1; }
+
+.mp-filter-btn--active {
+  opacity: 1;
+  color: var(--accent);
+  border-color: var(--accent);
+}
+
 .mp-section-title {
   font-size: 15px;
   font-weight: 600;
   color: var(--text-muted);
   text-transform: uppercase;
   letter-spacing: 0.06em;
+  margin-bottom: 0;
   margin: 0 0 1rem;
 }