feat: implement station navigation and update to SDK 37

- Implement `seekToNext` and `seekToPrevious` in `PlayerService` to allow switching between radio stations.
- Update `compileSdk` and `targetSdk` to 37 and bump version to 14.6.
- Modify `PlayerService` to remain active while paused to improve playback resumption.
- Modernize media resumption logic using Media3 `isRecent` check instead of legacy extras.
- Refactor `DefaultRenderersFactory` to use non-nullable `AudioSink` return types.
- General code cleanup using KTX extensions (e.g., `View.isEmpty()`) and Kotlin property access syntax.

app/src/main/java/com/michatec/radio/helpers/ExtrasHelper.kt

@@ -11,6 +11,7 @@ import android.widget.FrameLayout
 import androidx.preference.Preference
 import androidx.preference.PreferenceViewHolder
 import com.michatec.radio.R
+import androidx.core.view.isEmpty
 
 class ExtrasHelper {
     companion object {
@@ -69,7 +70,7 @@ class ExtrasHelper {
                 if (currentParent != container) {
                     currentParent?.removeView(visualizerView)
                     // If we injected into a standard preference, don't clear everything, just add
-                    if (container is FrameLayout || container.childCount == 0) {
+                    if (container is FrameLayout || container.isEmpty()) {
                         container.removeAllViews()
                     }
                     container.addView(visualizerView)