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/duskdolphin/audio/audiostreamdolphin.c

@@ -74,7 +74,7 @@ errorret_t audioStreamDolphinBuffer(audiostream_t *stream) {
 
   float_t leftFactor, rightFactor;
   audioStreamGetPanFactors(stream, &leftFactor, &rightFactor);
-  const float_t baseVolume = (float_t) stream->volume / 255.0f;
+  const float_t baseVolume = stream->volume;
   stream->platform.volumeLeft = (s32) mathClamp(baseVolume * leftFactor * MAX_VOLUME, 0, MAX_VOLUME);
   stream->platform.volumeRight = (s32) mathClamp(baseVolume * rightFactor * MAX_VOLUME, 0, MAX_VOLUME);