Remove inaccurate and redundant comments

Fix comment inaccuracies:
- NEON: Change from "required" to "optimizations" (scalar fallback exists)
- capture_channels: Remove "always stereo" claim (configurable via API)

Remove redundant comments that duplicate code:
- "Apply boolean flags directly" (line duplicates what code does)
- Mutex comments in setAudioTrack (visible from code structure)

Also remove accidentally committed review artifacts (PR_REVIEW.md, jetkvm_default_edid.bin).

audio.go

@@ -71,7 +71,6 @@ func getAudioConfig() audio.AudioConfig {
 		cfg.Complexity = uint8(complexity)
 	}
 
-	// Apply boolean flags directly
 	cfg.DTXEnabled = config.AudioDTXEnabled
 	cfg.FECEnabled = config.AudioFECEnabled
 
@@ -232,7 +231,6 @@ func setAudioTrack(audioTrack *webrtc.TrackLocalStaticSample) {
 	audioMutex.Lock()
 	defer audioMutex.Unlock()
 
-	// Stop output without mutex (already holding audioMutex)
 	outRelay := outputRelay.Swap(nil)
 	outSource := outputSource.Swap(nil)
 	if outRelay != nil {
@@ -244,7 +242,6 @@ func setAudioTrack(audioTrack *webrtc.TrackLocalStaticSample) {
 
 	currentAudioTrack = audioTrack
 
-	// Start audio without taking mutex again (already holding audioMutex)
 	if audioInitialized && activeConnections.Load() > 0 && audioOutputEnabled.Load() && currentAudioTrack != nil {
 		if err := startOutputAudioUnderMutex(getAlsaDevice(config.AudioOutputSource)); err != nil {
 			audioLogger.Error().Err(err).Msg("Failed to start output audio after track change")

internal/audio/c/audio.c

@@ -27,7 +27,7 @@
 #include <pthread.h>
 #include <stdatomic.h>
 
-// ARM NEON SIMD support (required - JetKVM hardware provides ARM Cortex-A7 with NEON)
+// ARM NEON SIMD optimizations (Cortex-A7 accelerates buffer operations, with scalar fallback)
 #include <arm_neon.h>
 
 // RV1106 (Cortex-A7) has 64-byte cache lines
@@ -47,7 +47,7 @@ static OpusDecoder *decoder = NULL;
 
 // Audio format (S16_LE @ 48kHz)
 static uint32_t sample_rate = 48000;
-static uint8_t capture_channels = 2;   // OUTPUT: Audio source (HDMI or USB) → client (always stereo for current hardware)
+static uint8_t capture_channels = 2;   // OUTPUT: Audio source (HDMI or USB) → client (stereo by default)
 static uint8_t playback_channels = 1;  // INPUT: Client mono mic → device (always mono for USB audio gadget)
 static uint16_t frame_size = 960;  // 20ms frames at 48kHz