Use SQLite for library management

Application/AppCoordinator.swift

@@ -2,6 +2,7 @@ import SwiftUI
 
 class AppCoordinator: ObservableObject {
     // MARK: - Managers
+    static var shared: AppCoordinator?
     let libraryManager: LibraryManager
     let playlistManager: PlaylistManager
     let audioPlayerManager: AudioPlayerManager
@@ -24,5 +25,6 @@ class AppCoordinator: ObservableObject {
         // Setup now playing
         nowPlayingManager = NowPlayingManager()
         nowPlayingManager.connectRemoteCommandCenter(audioPlayer: audioPlayerManager, playlistManager: playlistManager)
+        Self.shared = self
     }
 }

Application/AppDelegate.swift

@@ -14,10 +14,32 @@ class AppDelegate: NSObject, NSApplicationDelegate {
 
     func applicationWillTerminate(_ notification: Notification) {
         print("App is terminating...")
-        // Any cleanup code can go here
+        // Stop audio playback cleanly
+        if let coordinator = AppCoordinator.shared {
+            coordinator.audioPlayerManager.stop()
+        }
     }
 
     func applicationDidFinishLaunching(_ notification: Notification) {
         print("App finished launching")
+
+        // Ensure main window is visible
+        if let window = NSApp.windows.first {
+            window.makeKeyAndOrderFront(nil)
+        }
+    }
+
+    func applicationShouldHandleReopen(_ sender: NSApplication, hasVisibleWindows flag: Bool) -> Bool {
+        // If no windows are visible, show the main window
+        if !flag {
+            // Create a new window if needed
+            if NSApp.windows.isEmpty {
+                // The window should be created by SwiftUI, just make it visible
+                NSApp.activate(ignoringOtherApps: true)
+            } else if let window = NSApp.windows.first {
+                window.makeKeyAndOrderFront(nil)
+            }
+        }
+        return true
     }
 }

Managers/AudioPlayerManager.swift

@@ -27,7 +27,9 @@ class AudioPlayerManager: ObservableObject {
     }
 
     deinit {
+        stop()
         timer?.invalidate()
+        timer = nil
     }
 
     // MARK: - Playback Controls