Add support for Android TV and update dependencies

*   Implement initial Android TV support, including `LEANBACK_LAUNCHER` intent filter, hardware feature declarations, and television-specific layouts for the player, search results, and dialogs.
*   Add a splash/loading screen for the TV interface and a dedicated `SplashTheme`.
*   Improve DPAD navigation by adding `OnKeyListener` for station cards and allowing focus on internal elements.
*   Update `LayoutHolder` and `PlayerFragment` to handle TV layouts and add previous/next station navigation buttons.
*   Adjust `PreferencesHelper` to disable station editing by default on TV devices.
*   Update `androidx.media3` to v1.10.0, `work-runtime-ktx` to v2.11.2, and add `androidx.leanback` dependency.
*   Bump `versionCode` to 144 and `versionName` to 14.4.
*   Refactor `PlayerService` to simplify sleep timer cancellation logic.
*   Remove stale copyright headers and license comments from several Kotlin files.

app/src/main/java/com/michatec/radio/MainActivity.kt

@@ -15,7 +15,11 @@
 package com.michatec.radio
 
 import android.content.SharedPreferences
+import android.content.pm.PackageManager
 import android.os.Bundle
+import android.os.Handler
+import android.os.Looper
+import android.view.View
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.widget.Toolbar
 import androidx.navigation.fragment.NavHostFragment
@@ -38,6 +42,7 @@ class MainActivity : AppCompatActivity() {
 
     /* Overrides onCreate from AppCompatActivity */
     override fun onCreate(savedInstanceState: Bundle?) {
+        setTheme(R.style.AppTheme)
         super.onCreate(savedInstanceState)
         
         // Free Android
@@ -58,6 +63,15 @@ class MainActivity : AppCompatActivity() {
         NavigationUI.setupWithNavController(toolbar, navController, appBarConfiguration)
         supportActionBar?.hide()
 
+        // TV-specific loading logic
+        if (packageManager.hasSystemFeature(PackageManager.FEATURE_LEANBACK)) {
+            Handler(Looper.getMainLooper()).postDelayed({
+                findViewById<View>(R.id.loading_layout)?.visibility = View.GONE
+            }, 1500)
+        } else {
+            findViewById<View>(R.id.loading_layout)?.visibility = View.GONE
+        }
+
         // register listener for changes in shared preferences
         PreferencesHelper.registerPreferenceChangeListener(sharedPreferenceChangeListener)
     }