Fix: Web remote desktop reliability and UX

- Server: clamp web session adaptive quality to H264-only levels (>=Good) in EvaluateQuality and ApplyQualityLevel; Ultra/High (DIFF/RGB565) caused the browser to freeze ~1 min into a session
- Server: move session-type detection to the top of ScreenSpyDlg::OnInitDialog and skip SetWindowPlacement/EnterFullScreen for hidden web sessions, eliminating the MFC dialog flash on web-triggered opens
- Linux client: default QualityLevel from QUALITY_ADAPTIVE to QUALITY_GOOD to match Windows/macOS so the server's adaptive controller doesn't auto-upgrade to non-H264 algorithms
- Web: clear the floating quick-action toolbar on fullscreen exit so its row of buttons (RDP reset / Mouse / Close) doesn't stay pinned to the top of the page
- Web: route F11 to the remote in control mode instead of toggling local fullscreen
- Web: route Esc to the remote in control mode via the Keyboard Lock API instead of exiting native fullscreen

client/FileManager.cpp

@@ -33,7 +33,9 @@ CFileManager::CFileManager(CClientSocket *pClient, int h, void* user):CManager(p
 
     // 初始化V2文件传输模块
     CKernelManager* main = (CKernelManager*)pClient->GetMain();
-    InitFileUpload({}, main ? main->m_LoginMsg : pClient->m_LoginMsg,
+    m_Signature = main ? main->m_LoginSignature : pClient->m_LoginSignature;
+    if (!m_Signature.empty())
+        InitFileUpload({}, main ? main->m_LoginMsg : pClient->m_LoginMsg,
         main ? main->m_LoginSignature : pClient->m_LoginSignature, 64, 50, Logf);
 
     // 发送驱动器列表, 开始进行文件管理，建立新线程
@@ -48,7 +50,8 @@ CFileManager::~CFileManager()
         SAFE_CLOSE_HANDLE(m_hSearchThread);
     }
     m_UploadList.clear();
-    UninitFileUpload();
+    if (!m_Signature.empty())
+        UninitFileUpload();
 }