Add Cast button to NowPlayingBar and FullScreenNowPlaying

- Add Cast icon from lucide-svelte
- Add onCast callback prop to both components
- Show "Casting coming soon" toast when clicked
- Backend cast module is disabled pending fixes

src/lib/components/FullScreenNowPlaying.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { X, Shuffle, SkipBack, Play, Pause, SkipForward, Repeat, Heart, List, Mic2, Maximize2, MoreHorizontal } from 'lucide-svelte';
+  import { X, Shuffle, SkipBack, Play, Pause, SkipForward, Repeat, Heart, List, Mic2, Maximize2, MoreHorizontal, Cast } from 'lucide-svelte';
   import QualityBadge from './QualityBadge.svelte';
 
   interface Props {
@@ -30,6 +30,7 @@
     onToggleFavorite: () => void;
     onOpenQueue?: () => void;
     onOpenFocusMode?: () => void;
+    onCast?: () => void;
   }
 
   let {
@@ -59,7 +60,8 @@
     isFavorite,
     onToggleFavorite,
     onOpenQueue,
-    onOpenFocusMode
+    onOpenFocusMode,
+    onCast
   }: Props = $props();
 
   let progressRef: HTMLDivElement;
@@ -220,6 +222,9 @@
       <button class="action-btn" onclick={onOpenFocusMode}>
         <Maximize2 size={24} />
       </button>
+      <button class="action-btn" onclick={onCast} title="Cast to device">
+        <Cast size={24} />
+      </button>
       <button class="action-btn">
         <Mic2 size={24} />
       </button>

src/lib/components/NowPlayingBar.svelte

@@ -11,7 +11,8 @@
     List,
     Volume2,
     VolumeX,
-    Volume1
+    Volume1,
+    Cast
   } from 'lucide-svelte';
   import QualityBadge from './QualityBadge.svelte';
 
@@ -40,6 +41,7 @@
     onToggleFavorite?: () => void;
     onOpenQueue?: () => void;
     onOpenFullScreen?: () => void;
+    onCast?: () => void;
   }
 
   let {
@@ -66,7 +68,8 @@
     isFavorite = false,
     onToggleFavorite,
     onOpenQueue,
-    onOpenFullScreen
+    onOpenFullScreen,
+    onCast
   }: Props = $props();
 
   let progressRef: HTMLDivElement;
@@ -236,6 +239,9 @@
     <button class="action-btn" onclick={onOpenQueue}>
       <List size={20} />
     </button>
+    <button class="action-btn" onclick={onCast} title="Cast to device">
+      <Cast size={20} />
+    </button>
 
     <!-- Volume Control -->
     <div class="volume-control">

src/routes/+page.svelte

@@ -1529,11 +1529,13 @@
         onToggleFavorite={toggleFavorite}
         onOpenQueue={() => (isQueueOpen = true)}
         onOpenFullScreen={() => (isFullScreenOpen = true)}
+        onCast={() => showToast('Casting coming soon', 'info')}
       />
     {:else}
       <NowPlayingBar
         onOpenQueue={() => (isQueueOpen = true)}
         onOpenFullScreen={() => (isFullScreenOpen = true)}
+        onCast={() => showToast('Casting coming soon', 'info')}
       />
     {/if}
 
@@ -1584,6 +1586,7 @@
           isFullScreenOpen = false;
           isFocusModeOpen = true;
         }}
+        onCast={() => showToast('Casting coming soon', 'info')}
       />
     {/if}