Improve: Show host remark instead of IP in remote desktop dialog titles

When an online host has a remark set in the client list, use it in place of
the IP in the remote desktop ("远程桌面控制") and virtual screen ("远程虚拟屏幕")
dialog titles, falling back to the IP when no remark is present.

Add a GetTitleHostName() helper to both dialogs. CScreenSpyDlg resolves the
remark through its parent dialog's client map, while CHideScreenSpyDlg uses
the global g_2015RemoteDlg pointer; each falls back to m_IPAddress when the
host has no remark.

Co-Authored-By: deepseek-v4-pro

server/2015Remote/HideScreenSpyDlg.h

@@ -72,6 +72,9 @@ protected:
     bool JPG_BMP(int cbit, void* input, int inlen, void* output);
     void ResetScreen();
 
+    // 标题栏显示的主机名：有备注用备注，否则用 IP
+    CString GetTitleHostName() const;
+
     HDC                 m_hFullDC, m_hFullMemDC;
     HBITMAP	            m_BitmapHandle;
     LPVOID              m_BitmapData_Full;