Fix code quality: trailing whitespace, unused imports, clippy warnings

- Fix trailing whitespace in kex.rs and s3.rs
- Add missing KexProposal import in kex_complete.rs
- Auto-fix clippy warnings across all crates
- All 153 tests pass

markbase-core/src/ssh_server/version.rs

@@ -2,8 +2,8 @@
 // 参考OpenSSH sshd.c: ssh_exchange_identification()
 
 use anyhow::Result;
+use log::{debug, info};
 use std::io::{Read, Write};
-use log::{info, debug};
 
 /// SSH版本字符串
 pub const SSH_VERSION: &str = "SSH-2.0-MarkBaseSSH_1.0";
@@ -15,93 +15,96 @@ impl VersionExchange {
     /// 执行版本交换（服务器端）
     pub fn exchange<T: Read + Write>(stream: &mut T) -> Result<String> {
         info!("Starting SSH version exchange");
-        
+
         // 1. 发送服务器版本
         Self::send_version(stream)?;
-        
+
         // 2. 接收客户端版本
         let client_version = Self::receive_version(stream)?;
-        
-        info!("Version exchange completed: server={}, client={}", SSH_VERSION, client_version);
+
+        info!(
+            "Version exchange completed: server={}, client={}",
+            SSH_VERSION, client_version
+        );
         Ok(client_version)
     }
-    
+
     /// 发送服务器版本（参考OpenSSH ssh_exchange_identification）
     fn send_version<T: Write>(stream: &mut T) -> Result<()> {
         let version_line = format!("{}\r\n", SSH_VERSION);
         stream.write_all(version_line.as_bytes())?;
         stream.flush()?;
-        
+
         debug!("Sent version: {}", SSH_VERSION);
         Ok(())
     }
-    
+
     /// 接收客户端版本（参考OpenSSH ssh_exchange_identification）
     fn receive_version<T: Read>(stream: &mut T) -> Result<String> {
         let mut buffer = Vec::new();
         let mut byte = [0u8; 1];
-        
+
         // 读取直到遇到'\n'（参考OpenSSH实现）
         loop {
             stream.read_exact(&mut byte)?;
-            
+
             // OpenSSH兼容性处理：跳过前导空行和调试信息
-            if buffer.is_empty() && byte[0] == '\n' as u8 {
-                continue;  // 跳过空行
+            if buffer.is_empty() && byte[0] == b'\n' {
+                continue; // 跳过空行
             }
-            
+
             // 调试信息行（以'#'开头），跳过
-            if buffer.is_empty() && byte[0] == '#' as u8 {
+            if buffer.is_empty() && byte[0] == b'#' {
                 // 读取整行调试信息
-                while byte[0] != '\n' as u8 {
+                while byte[0] != b'\n' {
                     stream.read_exact(&mut byte)?;
                 }
                 buffer.clear();
                 continue;
             }
-            
+
             buffer.push(byte[0]);
-            
+
             // 遇到'\n'结束
-            if byte[0] == '\n' as u8 {
+            if byte[0] == b'\n' {
                 break;
             }
-            
+
             // 缓冲区溢出保护（OpenSSH限制：255字节）
             if buffer.len() > 255 {
                 return Err(anyhow::anyhow!("Version string too long"));
             }
         }
-        
+
         // 解析版本字符串
         let version_line = String::from_utf8(buffer)?;
         let version = version_line.trim().trim_matches('\r');
-        
+
         // 验证版本格式（SSH-2.0-*）
         if !version.starts_with("SSH-2.0-") {
             return Err(anyhow::anyhow!("Invalid SSH version: {}", version));
         }
-        
+
         debug!("Received version: {}", version);
         Ok(version.to_string())
     }
-    
+
     /// 解析客户端版本信息（兼容性检查）
     pub fn parse_client_version(version: &str) -> Result<ClientVersionInfo> {
         // 格式：SSH-protoversion-softwareversion SP comments
         let parts: Vec<&str> = version.split_whitespace().collect();
-        
+
         let main_part = parts.first().map_or(version, |v| v);
         let dash_parts: Vec<&str> = main_part.split('-').collect();
-        
+
         if dash_parts.len() < 3 {
             return Err(anyhow::anyhow!("Invalid version format: {}", version));
         }
-        
+
         let proto_version = dash_parts.get(1).map_or("2.0", |v| v);
         let software_version = dash_parts.get(2).map_or("unknown", |v| v);
         let comments = parts.get(1).map(|s| s.to_string());
-        
+
         Ok(ClientVersionInfo {
             proto_version: proto_version.to_string(),
             software_version: software_version.to_string(),
@@ -120,12 +123,12 @@ pub struct ClientVersionInfo {
 #[cfg(test)]
 mod tests {
     use super::*;
-    
+
     #[test]
     fn test_version_format() {
         assert!(SSH_VERSION.starts_with("SSH-2.0-"));
     }
-    
+
     #[test]
     fn test_parse_client_version() {
         let version = "SSH-2.0-OpenSSH_10.2";