feat(android): streaming cache budget and a hardware decoding switch

- Settings > Storage chooses the streaming cache's budget, 1 to 16 GiB,
  and shows what it holds against it. The bridge gains
  set_stream_cache_budget, which the next connection is built with and
  an open one evicts down to at once. Android keeps the choice in its own
  settings, like the desktop keeps it in desktop.json, and tells the
  engine as it is created. Unset stays at the shared 4 GiB default.
- Settings > Playback can turn hardware decoding off for a device whose
  decoder shows green or torn frames. pstr_mpv sets hwdec before each
  loadfile, so it applies from the next episode.

android/app/src/main/java/io/narl/protonstream/playback/NativeMpvHost.kt

@@ -184,12 +184,16 @@ class NativeMpvHost private constructor(private val nativeHandle: Long) : Libmpv
         audioLanguage: String?,
         subtitleLanguage: String?,
         subtitles: Boolean,
+        hardwareDecoding: Boolean,
     ) {
         check(size > 0uL) { "Cannot play an empty stream" }
         try {
             withContext(Dispatchers.IO) {
                 val loaded = withOpenHandle {
-                    nativeLoad(it, nativeHandle.toLong(), startPosition, audioLanguage, subtitleLanguage, subtitles).also { loaded ->
+                    nativeLoad(
+                        it, nativeHandle.toLong(), startPosition, audioLanguage, subtitleLanguage, subtitles,
+                        hardwareDecoding,
+                    ).also { loaded ->
                         if (loaded) {
                             // The outgoing stream is released by mpv closing it,
                             // not from here: `loadfile` is asynchronous and its
@@ -398,7 +402,15 @@ class NativeMpvHost private constructor(private val nativeHandle: Long) : Libmpv
     private external fun nativeDestroy(handle: Long)
     private external fun nativeAttachSurface(handle: Long, surface: Surface)
     private external fun nativeDetachSurface(handle: Long)
-    private external fun nativeLoad(handle: Long, stream: Long, start: Double, audio: String?, subtitle: String?, subtitles: Boolean): Boolean
+    private external fun nativeLoad(
+        handle: Long,
+        stream: Long,
+        start: Double,
+        audio: String?,
+        subtitle: String?,
+        subtitles: Boolean,
+        hardwareDecoding: Boolean,
+    ): Boolean
     private external fun nativePause(handle: Long, paused: Boolean)
     private external fun nativeSeek(handle: Long, position: Double)
     private external fun nativeVolume(handle: Long, volume: Double)

android/app/src/main/java/io/narl/protonstream/playback/PlayerScreen.kt

@@ -76,6 +76,7 @@ import androidx.compose.ui.viewinterop.AndroidView
 import androidx.core.view.WindowCompat
 import androidx.core.view.WindowInsetsCompat
 import androidx.core.view.WindowInsetsControllerCompat
+import io.narl.protonstream.settings.SettingsStore
 import io.narl.protonstream.native.NativeRuntime
 import io.narl.protonstream.ui.theme.AccentButton
 import io.narl.protonstream.ui.theme.AccentTrack
@@ -207,6 +208,7 @@ fun PlayerScreen(
             nativeHost.play(
                 key, startup.nativeHandle, startup.size, startup.startPosition,
                 startup.audioLanguage, startup.subtitleLanguage, startup.subtitles,
+                SettingsStore(context).hardwareDecoding,
             )
             // After the load, because mpv keeps none of the three across one.
             nativeHost.setVolume(startup.volume)

android/app/src/main/java/io/narl/protonstream/playback/StreamSession.kt

@@ -92,6 +92,7 @@ interface LibmpvHost {
         audioLanguage: String? = null,
         subtitleLanguage: String? = null,
         subtitles: Boolean = true,
+        hardwareDecoding: Boolean = true,
     )
 
     /** Calls pstr_android_stream_release exactly once for a published handle. */