refactor: 清理死代码和优化日志级别

- 删除未使用的函数和常量
  - create_public_key_message (rustdesk/connection)
  - decode_audio_packet, AudioPacketHeader (web/audio_ws)
  - io_error_to_hid_error, close_device, close_all_devices (hid)
  - shutdown_rx (rustdesk/mod)
  - CONNECT_TIMEOUT_MS, RESP_ERR_SEND_FAILED

- 调整日志级别
  - Session lagged: warn -> debug
  - 移除 H264 NAL trace 日志
  - 移除 Frame distribution lagged trace 日志
  - 移除 absolute mouse report trace 日志

- 优化 broadcast channel 缓冲区大小 8 -> 16

- 修复条件编译
  - static_files.rs: 添加 debug_assertions 条件

src/webrtc/peer.rs

@@ -383,7 +383,7 @@ pub struct PeerConnectionManager {
 impl PeerConnectionManager {
     /// Create a new peer connection manager
     pub fn new(config: WebRtcConfig) -> Self {
-        let (frame_tx, _) = broadcast::channel(16);
+        let (frame_tx, _) = broadcast::channel(16); // Buffer size 16 for low latency
 
         Self {
             config,
@@ -395,7 +395,7 @@ impl PeerConnectionManager {
 
     /// Create a new peer connection manager with HID controller
     pub fn with_hid(config: WebRtcConfig, hid: Arc<HidController>) -> Self {
-        let (frame_tx, _) = broadcast::channel(16);
+        let (frame_tx, _) = broadcast::channel(16); // Buffer size 16 for low latency
 
         Self {
             config,

src/webrtc/unified_video_track.rs

@@ -339,7 +339,6 @@ impl UnifiedVideoTrack {
                 _ => {}
             }
 
-            trace!("H264 NAL: type={} size={}", nal_type, nal.data.len());
             nals.push(nal.data.freeze());
         }
 

src/webrtc/universal_session.rs

@@ -573,7 +573,7 @@ impl UniversalSession {
                                 }
                             }
                             Err(broadcast::error::RecvError::Lagged(n)) => {
-                                warn!("Session {} lagged by {} frames", session_id, n);
+                                debug!("Session {} lagged by {} frames", session_id, n);
                             }
                             Err(broadcast::error::RecvError::Closed) => {
                                 info!("Video frame channel closed for session {}", session_id);

src/webrtc/video_track.rs

@@ -376,7 +376,6 @@ impl UniversalVideoTrack {
                 _ => {}
             }
 
-            trace!("H264 NAL: type={} size={}", nal_type, nal.data.len());
             nals.push(nal.data.freeze());
         }