refactor(audio/validation): improve frame data validation with specific error messages

Split generic frame data validation error into specific cases for empty and oversized frames to provide better error context. The optimized validation maintains performance while improving debuggability.

internal/audio/validation.go

@@ -14,6 +14,8 @@ var (
 	ErrInvalidAudioQuality    = errors.New("invalid audio quality level")
 	ErrInvalidFrameSize       = errors.New("invalid frame size")
 	ErrInvalidFrameData       = errors.New("invalid frame data")
+	ErrFrameDataEmpty         = errors.New("invalid frame data: frame data is empty")
+	ErrFrameDataTooLarge      = errors.New("invalid frame data: exceeds maximum")
 	ErrInvalidBufferSize      = errors.New("invalid buffer size")
 	ErrInvalidPriority        = errors.New("invalid priority value")
 	ErrInvalidLatency         = errors.New("invalid latency value")
@@ -325,11 +327,13 @@ func InitValidationCache() {
 //
 //go:inline
 func ValidateAudioFrame(data []byte) error {
-	// Single optimized check: empty data OR exceeds cached maximum
+	// Optimized validation with pre-allocated error messages for minimal overhead
-	// This branch prediction friendly pattern minimizes CPU pipeline stalls
 	dataLen := len(data)
-	if dataLen == 0 || dataLen > cachedMaxFrameSize {
+	if dataLen == 0 {
-		return ErrInvalidFrameData
+		return ErrFrameDataEmpty
+	}
+	if dataLen > cachedMaxFrameSize {
+		return ErrFrameDataTooLarge
 	}
 	return nil
 }