Doc cleanup: handoff + load-listener comment match shipped bullseye audio

Codex re-audit of 0cb315f was functional-green (81 tests, clean build,
device-green) with two non-runtime doc findings:
- SOUND_DESIGN_HANDOFF.md still described the retired "Level on lock,
  once, then silence" behavior. Now documents immediate bullseye
  alignment (enter <=0.2 / exit >=0.35 spatial hysteresis, no dwell) and
  the looping level.wav, with the velocity lock kept separate for
  lime/label/haptic.
- The SoundPool load listener's comment still said "one-shot Level";
  updated to describe the pending-loop-start path.

No code behavior change.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/src/main/java/com/onthelevel/feature/level/AudioLevelAssist.kt

@@ -148,8 +148,8 @@ private class SonarSoundPool(context: Context) {
         soundPool.setOnLoadCompleteListener { _, sampleId, status ->
             if (status == 0) {
                 loaded += sampleId
-                // The one-shot Level can't rely on a retry (the policy fires it once), so
-                // play a queued Level the moment its sample lands.
+                // If ALIGNED arrived before the Level sample finished loading, start the loop
+                // the moment it lands (ensureLevelLooping set levelPending instead of dropping it).
                 if (sampleId == levelSound && levelPending) {
                     levelPending = false
                     startLevelLoop()