Implement Upload Hook for momentry integration (Phase 1)

- Add upload_hook.rs module: trigger video_probe + video_register on upload
- Add UploadHookSection to config: video extensions, binary paths
- Integrate with SFTP: handle_close triggers hook on write files
- Integrate with SCP/rsync: child process exit triggers hook
- All 155 tests pass

markbase-core/src/security_audit/channel_security.rs

@@ -3,8 +3,7 @@ use std::path::PathBuf;
 
 #[test]
 fn test_channel_manager_creation() {
-    let manager = ChannelManager::new(PathBuf::from("/tmp"));
-    // Manager should be created successfully
+    let manager = ChannelManager::new(PathBuf::from("/tmp"), None, "test_user".to_string());
     assert!(true);
 }