feat(phase37): implement clickable context tooltip navigation

StackIcon Component:
- Now accepts onClick prop
- Changed from div to button element
- Added arrow (→) that appears on hover
- Tooltip text changed to "Click to go to: {source}"
- Visual feedback: hover background + active scale

Navigation Logic (+page.svelte):
- Added handleContextNavigation function
- Switch based on context_type:
  - album → handleAlbumClick
  - playlist → navigate + set selectedPlaylistId
  - artist_top → handleArtistClick
  - favorites → navigate to favorites
  - home_list → navigate to home
  - search → navigate to search
- Import getCurrentContext from playbackContextStore

UI Integration:
- ExpandedPlayer: Added onContextClick prop, passed to StackIcon
- FocusMode: Added onContextClick prop, passed to StackIcon
- Both receive handleContextNavigation callback

Phase 3.7 COMPLETE ✅

cp

src/lib/components/ExpandedPlayer.svelte

@@ -50,6 +50,7 @@
     onOpenFocusMode?: () => void;
     onCast?: () => void;
     isCastConnected?: boolean;
+    onContextClick?: () => void;
     // Lyrics props
     lyricsLines?: LyricsLine[];
     lyricsActiveIndex?: number;
@@ -89,6 +90,7 @@
     onOpenFocusMode,
     onCast,
     isCastConnected = false,
+    onContextClick,
     lyricsLines = [],
     lyricsActiveIndex = -1,
     lyricsActiveProgress = 0,
@@ -247,7 +249,7 @@
         <div class="track-info">
           <h1 class="title">{trackTitle}</h1>
           <div class="artist-album-row">
-            <StackIcon size={16} class="stack-icon" />
+            <StackIcon size={16} class="stack-icon" onClick={onContextClick} />
             <h2 class="artist">{artist}</h2>
             <span class="separator">·</span>
             <h3 class="album">{album}</h3>

src/lib/components/FocusMode.svelte

@@ -22,6 +22,7 @@
     currentTime: number;
     duration: number;
     onSeek: (time: number) => void;
+    onContextClick?: () => void;
     // Lyrics props
     lyricsLines?: LyricsLine[];
     lyricsActiveIndex?: number;
@@ -44,6 +45,7 @@
     currentTime,
     duration,
     onSeek,
+    onContextClick,
     lyricsLines = [],
     lyricsActiveIndex = -1,
     lyricsActiveProgress = 0,
@@ -187,7 +189,7 @@
         <div class="track-meta">
           <div class="track-title">{trackTitle}</div>
           <div class="track-artist-row">
-            <StackIcon size={12} class="stack-icon" />
+            <StackIcon size={12} class="stack-icon" onClick={onContextClick} />
             <div class="track-artist">{artist}</div>
           </div>
         </div>

src/lib/components/StackIcon.svelte

@@ -6,14 +6,23 @@
   interface Props {
     size?: number;
     class?: string;
+    onClick?: () => void;
   }
   
-  let { size = 16, class: className = '' }: Props = $props();
+  let { size = 16, class: className = '', onClick }: Props = $props();
   
   let context = $state(getCurrentContext());
   let displayInfo = $state(context ? getContextDisplayInfo() : null);
   let showIcon = $state(getCachedPreferences().show_context_icon);
 
+  function handleClick(e: MouseEvent) {
+    e.stopPropagation();
+    if (onClick) {
+      console.log('[StackIcon] Clicked - navigating to source');
+      onClick();
+    }
+  }
+
   // Subscribe to context changes
   $effect(() => {
     const unsubscribe = subscribe(() => {
@@ -43,9 +52,15 @@
 </script>
 
 {#if context && displayInfo && showIcon}
-  <div class="stack-icon-wrapper {className}" title="Playing from: {displayInfo}">
+  <button
+    class="stack-icon-wrapper {className}"
+    title="Click to go to: {displayInfo}"
+    onclick={handleClick}
+    type="button"
+  >
     <Layers size={size} strokeWidth={2} />
-  </div>
+    <span class="arrow">→</span>
+  </button>
 {/if}
 
 <style>
@@ -53,13 +68,36 @@
     display: inline-flex;
     align-items: center;
     justify-content: center;
+    gap: 4px;
     color: var(--text-secondary);
     opacity: 0.7;
-    transition: opacity 0.2s;
+    transition: all 0.2s;
     flex-shrink: 0;
+    background: none;
+    border: none;
+    padding: 4px 6px;
+    border-radius: 4px;
+    cursor: pointer;
+    font-size: 12px;
   }
   
   .stack-icon-wrapper:hover {
     opacity: 1;
+    background: rgba(255, 255, 255, 0.05);
+    color: var(--text-primary);
+  }
+
+  .stack-icon-wrapper:active {
+    transform: scale(0.95);
+  }
+
+  .arrow {
+    opacity: 0;
+    transition: opacity 0.2s;
+    margin-left: -2px;
+  }
+
+  .stack-icon-wrapper:hover .arrow {
+    opacity: 1;
   }
 </style>

src/routes/+page.svelte

@@ -29,7 +29,8 @@
   import { 
     initPlaybackContextStore,
     setPlaybackContext,
-    clearPlaybackContext 
+    clearPlaybackContext,
+    getCurrentContext
   } from '$lib/stores/playbackContextStore';
   import { 
     initPlaybackPreferences,
@@ -371,6 +372,66 @@
     }
   }
 
+  /**
+   * Navigate to the source of current playback context
+   */
+  async function handleContextNavigation() {
+    const context = getCurrentContext();
+    if (!context) {
+      console.log('[ContextNav] No context available');
+      return;
+    }
+
+    console.log('[ContextNav] Navigating to:', context);
+
+    try {
+      switch (context.context_type) {
+        case 'album':
+          // Navigate to album page
+          await handleAlbumClick(context.context_id);
+          break;
+
+        case 'playlist':
+          // Navigate to playlist page
+          const playlistId = parseInt(context.context_id);
+          if (!isNaN(playlistId)) {
+            selectedPlaylistId = playlistId;
+            navigateTo('playlist');
+          }
+          break;
+
+        case 'artist_top':
+          // Navigate to artist page
+          const artistId = parseInt(context.context_id);
+          if (!isNaN(artistId)) {
+            await handleArtistClick(artistId);
+          }
+          break;
+
+        case 'favorites':
+          // Navigate to favorites page
+          navigateTo('favorites');
+          break;
+
+        case 'home_list':
+          // Navigate to home page
+          navigateTo('home');
+          break;
+
+        case 'search':
+          // Navigate to search (could restore query if needed)
+          navigateTo('search');
+          break;
+
+        default:
+          console.warn('[ContextNav] Unknown context type:', context.context_type);
+      }
+    } catch (err) {
+      console.error('[ContextNav] Navigation failed:', err);
+      showToast('Failed to navigate to source', 'error');
+    }
+  }
+
   interface ArtistAlbumsResponse {
     items: QobuzAlbum[];
     total: number;
@@ -2201,6 +2262,7 @@
             handleAlbumClick(currentTrack.albumId);
           }
         }}
+        onContextClick={handleContextNavigation}
       />
     {:else}
       <NowPlayingBar
@@ -2293,6 +2355,7 @@
         lyricsSynced={lyricsIsSynced}
         lyricsLoading={lyricsStatus === 'loading'}
         lyricsError={lyricsStatus === 'error' ? lyricsError : (lyricsStatus === 'not_found' ? 'No lyrics found' : null)}
+        onContextClick={handleContextNavigation}
       />
     {/if}