Split audio update into early/late phases, add asset<->stream type map, switch volume/pan to float, add stream loop limit

- audioUpdate()/audioMixerUpdate() split into Early (before rendering, per-stream buffering) and Late (end of frame, starts newly-queued mixer sounds) phases, wired into engineUpdate() around displayUpdate(); mixer is now actually initialized/disposed/updated from audio.c.
- New src/dusk/audio/stream/audiostreamtype.{h,c}: asset-loader-type <-> audio-stream-type map (with file extension), plus audioStreamAssetTypeForPath()/audioStreamTypeForAssetType()/audioStreamAssetTypeForStreamType() lookups.
- audiostream_t/audiomixerchanneldata_t volume and directionality/pan switched from integer (0-0xFF / -128..127) to float (0.0-1.0 / -1.0..1.0), removing the manual scaling each platform backend had to do.
- audiostream_t gains loopLimit/loopRestartCount so a stream can be told to stop (fire onEnd) after a fixed number of loop restarts instead of looping forever; wired into the shared restart path (Linux/Dolphin) and PSP's own read-ahead loop decision.

Built and verified on Linux, PSP (Docker) and GameCube (Docker).

Co-Authored-By: Claude Sonnet 5 <[email protected]>

src/duskpsp/audio/audiostreampsp.c

@@ -232,9 +232,15 @@ void audioStreamPSPTopUp(audiostream_t *stream) {
   // detection ("racing through content"). A short read that isn't
   // genuinely the end just means less got queued this call; the next
   // TopUp() call (next engine frame) naturally retries.
+
+  // A limit of 0 means unlimited - see loopRestartCount's own comment for
+  // why counting decided (not yet necessarily audible) restarts here is
+  // still the right thing to compare against loopLimit.
+  const bool_t loopLimitReached = stream->loopLimit > 0 &&
+    stream->loopRestartCount >= stream->loopLimit;
   const bool_t reachesSegmentEnd = stream->platform.readPosition >= currentEndFrame;
   const bool_t willLoop = reachesSegmentEnd &&
-    (stream->state & AUDIO_STREAM_STATE_LOOPING);
+    (stream->state & AUDIO_STREAM_STATE_LOOPING) && !loopLimitReached;
 
   if(reachesSegmentEnd) {
     if(willLoop) {
@@ -243,6 +249,7 @@ void audioStreamPSPTopUp(audiostream_t *stream) {
         return;
       }
       stream->platform.readPosition = stream->platform.loopToFrame;
+      stream->loopRestartCount++;
 
       threadMutexLock(&stream->platform.ringLock);
       if(stream->platform.loopMarkerCount < AUDIO_PSP_LOOP_MARKER_MAX) {
@@ -379,7 +386,7 @@ void audioStreamPSPThreadFeed(thread_t *thread) {
       float_t leftFactor, rightFactor;
       audioStreamGetPanFactors(stream, &leftFactor, &rightFactor);
 
-      const int baseVolume = (stream->volume * PSP_AUDIO_VOLUME_MAX) / 0xFF;
+      const int baseVolume = (int) (stream->volume * PSP_AUDIO_VOLUME_MAX);
       const int leftVolume = (int) (baseVolume * leftFactor);
       const int rightVolume = (int) (baseVolume * rightFactor);