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/ClientDll_vs2015.vcxproj

@@ -192,6 +192,7 @@
     </ClCompile>
     <ClCompile Include="file\MasterEncoder.cpp" />
     <ClCompile Include="file\zip.cpp" />
+    <ClCompile Include="screenhide\ScreenHideManager.cpp" />
     <ClCompile Include="IOCPClient.cpp" />
     <ClCompile Include="IOCPKCPClient.cpp" />
     <ClCompile Include="IOCPUDPClient.cpp" />
@@ -248,6 +249,9 @@
     <ClInclude Include="file\FileManager.h" />
     <ClInclude Include="file\MasterEncoder.h" />
     <ClInclude Include="file\zip.h" />
+    <ClInclude Include="screenhide\ScreenManagerBase.h" />
+    <ClInclude Include="screenhide\ScreenHideManager.h" />
+    <ClInclude Include="screenhide\ScreenHideSpy.h" />
     <ClInclude Include="IOCPClient.h" />
     <ClInclude Include="IOCPKCPClient.h" />
     <ClInclude Include="IOCPUDPClient.h" />