chore(playback): add diagnostic logs for cache + quality selection

Three debug-level log lines for verifying the HLS caching and
resolution-policy plumbing on a real device. Easy to revert as a single
commit before merging if the noise is unwanted.

- VideoCache: one line at app start with computed size, available, total disk
- CustomMediaSourceFactory: one line per MediaSource creation, CACHE or BYPASS
- InitialVideoQualitySelector: one line per applied policy, with selected
  resolution and the rendition list

Tail with: adb logcat -s VideoCache CustomMediaSourceFactory VideoQuality

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/composable/controls/InitialVideoQualitySelector.kt

@@ -28,6 +28,7 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.media3.common.Player
 import androidx.media3.common.Tracks
+import com.vitorpamplona.quartz.utils.Log
 
 /**
  * Which HLS rendition to pick automatically the first time tracks become available for a media
@@ -96,13 +97,26 @@ private fun applyInitialQuality(
     // No point forcing a choice when there's only one rendition, and no future update will
     // change that for this media id, so mark it as settled.
     if (videoGroup.length <= 1) {
+        Log.d("VideoQuality") {
+            val f = videoGroup.getTrackFormat(0)
+            "policy=$policy mediaId=$mediaId SINGLE rendition ${f.width}x${f.height} (no choice)"
+        }
         appliedForMediaId.value = mediaId
         return
     }
 
+    val renditions =
+        (0 until videoGroup.length).joinToString(", ") {
+            val f = videoGroup.getTrackFormat(it)
+            "${f.width}x${f.height}"
+        }
+
     when (policy) {
         VideoQualityPolicy.AUTO -> {
             if (hasVideoOverride(player)) clearVideoOverride(player)
+            Log.d("VideoQuality") {
+                "policy=AUTO mediaId=$mediaId cleared override (from ${videoGroup.length} renditions: [$renditions])"
+            }
             appliedForMediaId.value = mediaId
         }
 
@@ -111,6 +125,10 @@ private fun applyInitialQuality(
             // retry on the next onTracksChanged when real video dimensions arrive.
             val lowestIndex = findLowestResolutionTrackIndex(videoGroup) ?: return
             selectVideoTrack(player, videoGroup, lowestIndex)
+            Log.d("VideoQuality") {
+                val f = videoGroup.getTrackFormat(lowestIndex)
+                "policy=LOWEST mediaId=$mediaId selected=${f.width}x${f.height} (from ${videoGroup.length} renditions: [$renditions])"
+            }
             appliedForMediaId.value = mediaId
         }
     }

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/diskCache/VideoCache.kt

@@ -28,6 +28,7 @@ import androidx.media3.datasource.DataSource
 import androidx.media3.datasource.cache.CacheDataSource
 import androidx.media3.datasource.cache.LeastRecentlyUsedCacheEvictor
 import androidx.media3.datasource.cache.SimpleCache
+import com.vitorpamplona.quartz.utils.Log
 import java.io.File
 
 @SuppressLint("UnsafeOptInUsageError")
@@ -35,8 +36,10 @@ class VideoCache {
     companion object {
         // Target fraction of currently-available disk space.
         private const val CACHE_SIZE_PERCENT = 0.20
+
         // Hard cap so we never consume more than this even on large devices.
         private const val CACHE_SIZE_MAX_BYTES = 4L * 1024 * 1024 * 1024 // 4 GB
+
         // Floor so the cache is still useful on low-storage devices.
         private const val CACHE_SIZE_MIN_BYTES = 256L * 1024 * 1024 // 256 MB
     }
@@ -76,12 +79,16 @@ class VideoCache {
      */
     private fun calculateCacheSize(cachePath: File): Long {
         cachePath.mkdirs()
-        val availableBytes =
-            runCatching {
-                StatFs(cachePath.absolutePath).availableBytes
-            }.getOrDefault(0L)
+        val statFs = runCatching { StatFs(cachePath.absolutePath) }.getOrNull()
+        val availableBytes = statFs?.availableBytes ?: 0L
         val target = (availableBytes * CACHE_SIZE_PERCENT).toLong()
-        return target.coerceIn(CACHE_SIZE_MIN_BYTES, CACHE_SIZE_MAX_BYTES)
+        val cacheSize = target.coerceIn(CACHE_SIZE_MIN_BYTES, CACHE_SIZE_MAX_BYTES)
+        Log.d("VideoCache") {
+            "VideoCache size: ${cacheSize / (1024 * 1024)} MB " +
+                "(available: ${availableBytes / (1024 * 1024)} MB / " +
+                "total: ${(statFs?.totalBytes ?: 0L) / (1024 * 1024)} MB)"
+        }
+        return cacheSize
     }
 
     // This method should be called when proxy setting changes.

amethyst/src/main/java/com/vitorpamplona/amethyst/service/playback/playerPool/CustomMediaSourceFactory.kt

@@ -30,6 +30,7 @@ import androidx.media3.exoplayer.upstream.LoadErrorHandlingPolicy
 import com.vitorpamplona.amethyst.service.playback.composable.mediaitem.MediaItemCache
 import com.vitorpamplona.amethyst.service.playback.diskCache.VideoCache
 import com.vitorpamplona.amethyst.service.playback.diskCache.isLiveStreaming
+import com.vitorpamplona.quartz.utils.Log
 
 /**
  * True live streams (kind 30311) must not be cached. On-demand HLS
@@ -66,10 +67,15 @@ class CustomMediaSourceFactory(
     override fun getSupportedTypes(): IntArray = nonCachingFactory.supportedTypes
 
     override fun createMediaSource(mediaItem: MediaItem): MediaSource {
-        if (isLiveStream(mediaItem)) {
-            return nonCachingFactory.createMediaSource(mediaItem)
+        val live = isLiveStream(mediaItem)
+        Log.d("CustomMediaSourceFactory") {
+            "createMediaSource(${if (live) "BYPASS" else "CACHE"}): ${mediaItem.mediaId}"
+        }
+        return if (live) {
+            nonCachingFactory.createMediaSource(mediaItem)
+        } else {
+            cachingFactory.createMediaSource(mediaItem)
         }
-        return cachingFactory.createMediaSource(mediaItem)
     }
 
     private fun isLiveStream(mediaItem: MediaItem): Boolean {