fix: Address linting errors in audio code

- Check SetReadDeadline error in IPC client
- Explicitly ignore Kill() error (process may be dead)
- Remove init() function and rely on explicit ExtractEmbeddedBinaries() call

internal/audio/embed.go

@@ -15,10 +15,10 @@ var audioOutputBinary []byte
 var audioInputBinary []byte
 
 const (
-	audioBinDir         = "/userdata/jetkvm/bin"
-	audioOutputBinPath  = audioBinDir + "/jetkvm_audio_output"
-	audioInputBinPath   = audioBinDir + "/jetkvm_audio_input"
-	binaryFileMode      = 0755 // rwxr-xr-x
+	audioBinDir        = "/userdata/jetkvm/bin"
+	audioOutputBinPath = audioBinDir + "/jetkvm_audio_output"
+	audioInputBinPath  = audioBinDir + "/jetkvm_audio_input"
+	binaryFileMode     = 0755 // rwxr-xr-x
 )
 
 // ExtractEmbeddedBinaries extracts the embedded C audio binaries to disk
@@ -78,13 +78,3 @@ func GetAudioOutputBinaryPath() string {
 func GetAudioInputBinaryPath() string {
 	return audioInputBinPath
 }
-
-// init ensures binaries are extracted when package is imported
-func init() {
-	// Extract binaries on package initialization
-	// This ensures binaries are available before supervisors start
-	if err := ExtractEmbeddedBinaries(); err != nil {
-		// Log error but don't panic - let caller handle initialization failure
-		fmt.Fprintf(os.Stderr, "Warning: Failed to extract embedded audio binaries: %v\n", err)
-	}
-}

internal/audio/ipc.go

@@ -22,15 +22,15 @@ var writeBufferPool = sync.Pool{
 
 // IPC Protocol constants (matches C implementation in ipc_protocol.h)
 const (
-	ipcMagicOutput    = 0x4A4B4F55 // "JKOU" - Output (device → browser)
-	ipcMagicInput     = 0x4A4B4D49 // "JKMI" - Input (browser → device)
-	ipcHeaderSize     = 9          // Reduced from 17 (removed 8-byte timestamp)
-	ipcMaxFrameSize   = 1024       // 128kbps @ 20ms = ~600 bytes worst case with VBR+FEC
-	ipcMsgTypeOpus    = 0
-	ipcMsgTypeConfig  = 1
-	ipcMsgTypeStop    = 3
-	connectTimeout    = 5 * time.Second
-	readTimeout       = 2 * time.Second
+	ipcMagicOutput   = 0x4A4B4F55 // "JKOU" - Output (device → browser)
+	ipcMagicInput    = 0x4A4B4D49 // "JKMI" - Input (browser → device)
+	ipcHeaderSize    = 9          // Reduced from 17 (removed 8-byte timestamp)
+	ipcMaxFrameSize  = 1024       // 128kbps @ 20ms = ~600 bytes worst case with VBR+FEC
+	ipcMsgTypeOpus   = 0
+	ipcMsgTypeConfig = 1
+	ipcMsgTypeStop   = 3
+	connectTimeout   = 5 * time.Second
+	readTimeout      = 2 * time.Second
 )
 
 // IPCClient manages Unix socket communication with audio subprocess
@@ -109,7 +109,9 @@ func (c *IPCClient) ReadMessage() (uint8, []byte, error) {
 	}
 
 	// Set read deadline
-	c.conn.SetReadDeadline(time.Now().Add(readTimeout))
+	if err := c.conn.SetReadDeadline(time.Now().Add(readTimeout)); err != nil {
+		return 0, nil, fmt.Errorf("failed to set read deadline: %w", err)
+	}
 
 	// Read 9-byte header
 	var header [ipcHeaderSize]byte

internal/audio/supervisor.go

@@ -21,12 +21,12 @@ type Supervisor struct {
 	socketPath string
 	env        []string
 
-	cmd        *exec.Cmd
-	ctx        context.Context
-	cancel     context.CancelFunc
-	running    atomic.Bool
-	done       chan struct{} // Closed when supervision loop exits
-	logger     zerolog.Logger
+	cmd     *exec.Cmd
+	ctx     context.Context
+	cancel  context.CancelFunc
+	running atomic.Bool
+	done    chan struct{} // Closed when supervision loop exits
+	logger  zerolog.Logger
 
 	// Restart state
 	restartCount   uint8
@@ -81,7 +81,7 @@ func (s *Supervisor) Stop() {
 
 	// Kill process if running
 	if s.cmd != nil && s.cmd.Process != nil {
-		s.cmd.Process.Kill()
+		_ = s.cmd.Process.Kill() // Ignore error, process may already be dead
 	}
 
 	// Wait for supervision loop to exit

internal/usbgadget/config.go

@@ -66,14 +66,14 @@ var defaultGadgetConfig = map[string]gadgetConfigItem{
 		path:       []string{"functions", "uac1.usb0"},
 		configPath: []string{"uac1.usb0"},
 		attrs: gadgetAttributes{
-			"p_chmask":         "3",      // Playback: stereo (2 channels)
-			"p_srate":          "48000",  // Playback: 48kHz sample rate
-			"p_ssize":          "2",      // Playback: 16-bit (2 bytes)
-			"p_volume_present": "0",      // Playback: no volume control
-			"c_chmask":         "3",      // Capture: stereo (2 channels)
-			"c_srate":          "48000",  // Capture: 48kHz sample rate
-			"c_ssize":          "2",      // Capture: 16-bit (2 bytes)
-			"c_volume_present": "0",      // Capture: no volume control
+			"p_chmask":         "3",     // Playback: stereo (2 channels)
+			"p_srate":          "48000", // Playback: 48kHz sample rate
+			"p_ssize":          "2",     // Playback: 16-bit (2 bytes)
+			"p_volume_present": "0",     // Playback: no volume control
+			"c_chmask":         "3",     // Capture: stereo (2 channels)
+			"c_srate":          "48000", // Capture: 48kHz sample rate
+			"c_ssize":          "2",     // Capture: 16-bit (2 bytes)
+			"c_volume_present": "0",     // Capture: no volume control
 		},
 	},
 }