feat: wire TrackContextMenuConfig to bottom controls and track table

Extract shared `trackContextMenuConfig` computed property and pass it to
both TrackTableView and PlayerControlsView, so right-clicking the now-playing
area shows the same context menu as right-clicking a track row.

Music/ContentView.swift

@@ -178,20 +178,7 @@ struct ContentView: View {
                             player.setQueue(trackList)
                             player.play(track)
                         },
-                        playlists: playlist.playlists,
-                        lastUsedPlaylistName: playlist.lastUsedPlaylistName,
-                        selectedPlaylist: playlist.selectedPlaylist,
-                        onAddToPlaylist: { track, targetPlaylist in
-                            try? playlist.addTrack(track, to: targetPlaylist)
-                        },
-                        onAddToLastPlaylist: { track in
-                            try? playlist.addTrackToLastUsedPlaylist(track)
-                        },
-                        onRemoveFromPlaylist: playlist.selectedPlaylist != nil ? { track in
-                            if let selected = playlist.selectedPlaylist {
-                                try? playlist.removeTrack(track, from: selected)
-                            }
-                        } : nil,
+                        contextMenuConfig: trackContextMenuConfig,
                         onReorder: playlist.selectedPlaylist != nil ? { from, to in
                             if let selected = playlist.selectedPlaylist {
                                 try? playlist.moveTrack(in: selected, from: from, to: to)
@@ -368,6 +355,25 @@ struct ContentView: View {
         }
     }
 
+    private var trackContextMenuConfig: TrackContextMenuConfig {
+        TrackContextMenuConfig(
+            playlists: playlist.playlists,
+            lastUsedPlaylistName: playlist.lastUsedPlaylistName,
+            selectedPlaylist: playlist.selectedPlaylist,
+            onAddToPlaylist: { track, targetPlaylist in
+                try? playlist.addTrack(track, to: targetPlaylist)
+            },
+            onAddToLastPlaylist: { track in
+                try? playlist.addTrackToLastUsedPlaylist(track)
+            },
+            onRemoveFromPlaylist: playlist.selectedPlaylist != nil ? { track in
+                if let selected = playlist.selectedPlaylist {
+                    try? playlist.removeTrack(track, from: selected)
+                }
+            } : nil
+        )
+    }
+
     private var playerControls: some View {
         PlayerControlsView(
             currentTrack: player.currentTrack,
@@ -397,7 +403,8 @@ struct ContentView: View {
             onScrubEnd: { player.endScrubbing(at: $0) },
             onVolumeChange: { player.setVolume($0) },
             onShuffleToggle: { player.toggleShuffle() },
-            onNowPlayingTap: { scrollToPlayingTrigger = UUID() }
+            onNowPlayingTap: { scrollToPlayingTrigger = UUID() },
+            contextMenuConfig: trackContextMenuConfig
         )
     }