feat: Add 200% in-player volume boost for Android and iOS

Implemented in-player volume boost support up to 200% across Android and iOS playback engines.

Changes include:
- Added player-level volume control APIs to PlayerEngineController.
- Routed volume gestures through the active player engine instead of system volume when available.
- Added Android support by mapping boosted volume to ExoPlayer volume from 0.0 to 2.0.
- Added iOS support by exposing volume control through NuvioPlayerBridge.
- Configured MPV volume-max to 200 and mapped shared volume values to MPV volume 0–200.
- Updated player volume feedback to display boosted levels up to 200%.
- Preserved fallback behavior to system volume when the player controller is unavailable.

This keeps brightness and system volume behavior intact while allowing playback-specific volume amplification during video playback.

composeApp/src/androidMain/kotlin/com/nuvio/app/features/player/PlayerEngine.android.kt

@@ -393,6 +393,23 @@ actual fun PlatformPlayerSurface(
                     exoPlayer.setPlaybackSpeed(speed)
                 }
 
+                override fun currentPlayerVolume(): PlayerAudioLevel {
+                    val current = exoPlayer.volume.coerceIn(0f, 2f)
+                    return PlayerAudioLevel(
+                        fraction = current,
+                        isMuted = current <= 0.001f,
+                    )
+                }
+
+                override fun setPlayerVolume(level: Float): PlayerAudioLevel {
+                    val target = level.coerceIn(0f, 2f)
+                    exoPlayer.volume = target
+                    return PlayerAudioLevel(
+                        fraction = target,
+                        isMuted = target <= 0.001f,
+                    )
+                }
+
                 override fun getAudioTracks(): List<AudioTrack> =
                     exoPlayer.extractAudioTracks(context)
 

composeApp/src/commonMain/kotlin/com/nuvio/app/features/player/PlayerEngine.kt

@@ -10,6 +10,14 @@ interface PlayerEngineController {
     fun seekBy(offsetMs: Long)
     fun retry()
     fun setPlaybackSpeed(speed: Float)
+    fun currentPlayerVolume(): PlayerAudioLevel = PlayerAudioLevel(
+        fraction = 1f,
+        isMuted = false,
+    )
+    fun setPlayerVolume(level: Float): PlayerAudioLevel = PlayerAudioLevel(
+        fraction = 1f,
+        isMuted = false,
+    )
     fun getAudioTracks(): List<AudioTrack>
     fun getSubtitleTracks(): List<SubtitleTrack>
     fun selectAudioTrack(index: Int)

composeApp/src/commonMain/kotlin/com/nuvio/app/features/player/PlayerScreen.kt

@@ -105,6 +105,7 @@ private const val PlayerLockedOverlayDurationMs = 2_000L
 private const val PlayerLeftGestureBoundary = 0.4f
 private const val PlayerRightGestureBoundary = 0.6f
 private const val PlayerVerticalGestureSensitivity = 1f
+private const val PlayerMaxVolumeBoost = 2f
 private const val PlayerSeekProgressSyncDebounceMs = 700L
 private const val P2pInitialPreloadTargetBytes = 5_242_880L
 /** Hard ceiling for next-episode stream search to prevent hanging forever. */
@@ -993,7 +994,7 @@ fun PlayerScreen(
         }
 
         fun showVolumeFeedback(level: PlayerAudioLevel) {
-            val percentage = (level.fraction.coerceIn(0f, 1f) * 100f).roundToInt()
+            val percentage = (level.fraction.coerceIn(0f, PlayerMaxVolumeBoost) * 100f).roundToInt()
             showGestureFeedback(
                 GestureFeedbackState(
                     messageRes = if (level.isMuted) {
@@ -2344,7 +2345,7 @@ fun PlayerScreen(
                         },
                     )
                 }
-                .pointerInput(gestureController, layoutSize) {
+                .pointerInput(gestureController, playerController, layoutSize) {
                     awaitEachGesture {
                         val down = awaitFirstDown()
                         if (playerControlsLockedState.value) {
@@ -2371,7 +2372,7 @@ fun PlayerScreen(
                             null
                         }
                         val initialVolume = if (region == PlayerSideGesture.Volume) {
-                            controller?.currentVolume()
+                            playerController?.currentPlayerVolume() ?: controller?.currentVolume()
                         } else {
                             null
                         }
@@ -2456,8 +2457,11 @@ fun PlayerScreen(
                                 PlayerGestureMode.Volume -> {
                                     val gestureDeltaFraction =
                                         (-totalDy / height) * PlayerVerticalGestureSensitivity
-                                    controller?.setVolume((initialVolume?.fraction ?: 0f) + gestureDeltaFraction)
-                                        ?.let(showVolumeFeedbackState.value)
+                                    val target = ((initialVolume?.fraction ?: 1f) + gestureDeltaFraction)
+                                        .coerceIn(0f, PlayerMaxVolumeBoost)
+                                    val level = playerController?.setPlayerVolume(target)
+                                        ?: controller?.setVolume(target.coerceIn(0f, 1f))
+                                    level?.let(showVolumeFeedbackState.value)
                                 }
 
                                 null -> Unit

composeApp/src/iosMain/kotlin/com/nuvio/app/features/player/NuvioPlayerBridge.kt

@@ -31,6 +31,8 @@ interface NuvioPlayerBridge {
         gamma: Int,
     )
     fun setPlaybackSpeed(speed: Float)
+    fun getVolume(): Float
+    fun setVolume(volume: Float)
     fun setResizeMode(mode: Int) // 0=Fit, 1=Fill, 2=Zoom
     fun getAudioTrackCount(): Int
     fun getAudioTrackIndex(at: Int): Int

composeApp/src/iosMain/kotlin/com/nuvio/app/features/player/PlayerEngine.ios.kt

@@ -87,6 +87,23 @@ actual fun PlatformPlayerSurface(
                 bridge.setPlaybackSpeed(speed)
             }
 
+            override fun currentPlayerVolume(): PlayerAudioLevel {
+                val current = bridge.getVolume().coerceIn(0f, 2f)
+                return PlayerAudioLevel(
+                    fraction = current,
+                    isMuted = current <= 0.001f,
+                )
+            }
+
+            override fun setPlayerVolume(level: Float): PlayerAudioLevel {
+                val target = level.coerceIn(0f, 2f)
+                bridge.setVolume(target)
+                return PlayerAudioLevel(
+                    fraction = target,
+                    isMuted = target <= 0.001f,
+                )
+            }
+
             override fun getAudioTracks(): List<AudioTrack> {
                 val count = bridge.getAudioTrackCount()
                 return (0 until count).map { i ->

iosApp/iosApp/Player/MPVPlayerBridge.swift

@@ -60,6 +60,8 @@ final class MPVPlayerBridgeImpl: NSObject, NuvioPlayerBridge {
         )
     }
     func setPlaybackSpeed(speed: Float) { playerVC?.setSpeed(speed) }
+    func getVolume() -> Float { playerVC?.getVolume() ?? 1.0 }
+    func setVolume(volume: Float) { playerVC?.setVolume(volume) }
     func setResizeMode(mode: Int32) { playerVC?.setResize(Int(mode)) }
 
     // Audio tracks
@@ -319,6 +321,8 @@ final class MPVPlayerViewController: UIViewController {
         checkError(mpv_set_option_string(mpv, "hwdec", "auto"))
         checkError(mpv_set_option_string(mpv, "audio-channels", "stereo"))
         checkError(mpv_set_option_string(mpv, "audio-fallback-to-null", "yes"))
+        checkError(mpv_set_option_string(mpv, "volume-max", "200"))
+        checkError(mpv_set_option_string(mpv, "volume", "100"))
         checkError(mpv_set_option_string(mpv, "vulkan-swap-mode", "fifo"))
         checkError(mpv_set_option_string(mpv, "vulkan-queue-count", "1"))
         checkError(mpv_set_option_string(mpv, "vulkan-async-compute", "no"))
@@ -517,6 +521,18 @@ final class MPVPlayerViewController: UIViewController {
         mpv_set_property(mpv, "speed", MPV_FORMAT_DOUBLE, &s)
     }
 
+    func getVolume() -> Float {
+        guard mpv != nil else { return 1.0 }
+        let volume = getDouble("volume") / 100.0
+        return Float(max(0.0, min(2.0, volume)))
+    }
+
+    func setVolume(_ volume: Float) {
+        guard mpv != nil else { return }
+        var value = Double(max(0.0, min(2.0, volume)) * 100.0)
+        checkError(mpv_set_property(mpv, "volume", MPV_FORMAT_DOUBLE, &value))
+    }
+
     func setResize(_ mode: Int) {
         guard mpv != nil else { return }
         switch mode {