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/Keys.kt

@@ -1,17 +1,3 @@
-/*
- * Keys.kt
- * Implements the keys used throughout the app
- * This object hosts all keys used to control Radio state
- *
- * This file is part of
- * TRANSISTOR - Radio App for Android
- *
- * Copyright (c) 2015-22 - Y20K.org
- * Licensed under the MIT-License
- * http://opensource.org/licenses/MIT
- */
-
-
 package com.michatec.radio
 
 import java.util.*