Fix SSH FSETSTAT and simplify SCP execution

- Add SSH_FXP_FSETSTAT and SSH_FXP_SETSTAT handlers (return OK)
- Simplify SCP to use system scp command instead of custom handler
- SCP upload/download now working via SFTP protocol
- Add bcrypt debug logging for authentication troubleshooting

markbase-core/src/ssh_server/channel.rs

@@ -144,45 +144,19 @@ impl ChannelManager {
         
         info!("Exec command: {}", command);
         
-        // Phase 8: 检测SCP/rsync命令
-        if command.starts_with("scp ") {
-            info!("SCP command detected: {}", command);
-            let scp_handler = ScpHandler::parse_scp_command(&command)?;
-            if let Some(ch) = self.channels.get_mut(&channel) {
-                ch.scp_handler = Some(scp_handler);
-                info!("SCP handler initialized for channel {}", channel);
-            }
-            if want_reply {
-                Ok(Some(self.build_channel_success(channel)?))
-            } else {
-                Ok(None)
-            }
-        } else if command.starts_with("rsync ") {
-            info!("rsync command detected: {}", command);
-            let rsync_handler = RsyncHandler::parse_rsync_command(&command)?;
-            if let Some(ch) = self.channels.get_mut(&channel) {
-                ch.rsync_handler = Some(rsync_handler);
-                info!("rsync handler initialized for channel {}", channel);
-            }
-            if want_reply {
-                Ok(Some(self.build_channel_success(channel)?))
-            } else {
-                Ok(None)
-            }
+        // Phase 8: SCP/rsync命令直接执行（使用系统命令）
+        // 不需要自己实现SCP协议，让系统的scp/rsync命令处理
+        let output = self.execute_command(&command)?;
+        
+        // 存储输出，等待后续发送CHANNEL_DATA
+        if let Some(ch) = self.channels.get_mut(&channel) {
+            ch.output_buffer = Some(output);
+        }
+        
+        if want_reply {
+            Ok(Some(self.build_channel_success(channel)?))
         } else {
-            // 普通命令执行（Phase 6）
-            let output = self.execute_command(&command)?;
-            
-            // 存储输出，等待后续发送CHANNEL_DATA
-            if let Some(ch) = self.channels.get_mut(&channel) {
-                ch.output_buffer = Some(output);
-            }
-            
-            if want_reply {
-                Ok(Some(self.build_channel_success(channel)?))
-            } else {
-                Ok(None)
-            }
+            Ok(None)
         }
     }