Initial commit: RustDesk 1.4.7 macOS desktop port

- Filled empty libs/hbb_common/ submodule (cloned from rustdesk/hbb_common)
- Patched Flutter 3.44 / Dart 3.12 compatibility:
  * flutter/lib/generated_bridge.dart: asTypedList with cast<>, DartPort=Int64
  * flutter/lib/common.dart: DialogTheme->DialogThemeData, TabBarTheme->TabBarThemeData
  * flutter/pubspec.yaml: extended_text 14.0.0->15.0.2, google_fonts override 5.0.0
  * flutter/macos/Runner/Configs/Release.xcconfig: EXCLUDED_ARCHS=x86_64
- Build verified: cargo check + cargo build --features flutter + cargo build --release --features flutter
- Verified flutter build macos --debug and --release both produce working .app
- Verified .dmg installer (27MB arm64) created via hdiutil
- Build deps: Xcode 26.5, CocoaPods 1.16.2, Flutter 3.44, VCPKG arm64-osx

res/vcpkg/ffmpeg/vcpkg-cmake-wrapper.cmake

@@ -0,0 +1,47 @@
+set(FFMPEG_PREV_MODULE_PATH ${CMAKE_MODULE_PATH})
+list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR})
+
+include(SelectLibraryConfigurations)
+
+cmake_policy(SET CMP0012 NEW)
+
+set(vcpkg_no_avcodec_target ON)
+set(vcpkg_no_avformat_target ON)
+set(vcpkg_no_avutil_target ON)
+if(TARGET FFmpeg::avcodec)
+  set(vcpkg_no_avcodec_target OFF)
+endif()
+if(TARGET FFmpeg::avformat)
+  set(vcpkg_no_avformat_target OFF)
+endif()
+if(TARGET FFmpeg::avutil)
+  set(vcpkg_no_avutil_target OFF)
+endif()
+
+_find_package(${ARGS})
+
+if(WIN32)
+  set(PKG_CONFIG_EXECUTABLE "${CMAKE_CURRENT_LIST_DIR}/../../../@_HOST_TRIPLET@/tools/pkgconf/pkgconf.exe" CACHE STRING "" FORCE)
+endif()
+
+set(PKG_CONFIG_USE_CMAKE_PREFIX_PATH ON) # Required for CMAKE_MINIMUM_REQUIRED_VERSION VERSION_LESS 3.1 which otherwise ignores CMAKE_PREFIX_PATH
+
+if(@WITH_MFX@)
+  find_package(PkgConfig )
+  pkg_check_modules(libmfx  IMPORTED_TARGET libmfx)
+  list(APPEND FFMPEG_LIBRARIES PkgConfig::libmfx)
+  if(vcpkg_no_avcodec_target AND TARGET FFmpeg::avcodec)
+    target_link_libraries(FFmpeg::avcodec INTERFACE PkgConfig::libmfx)
+  endif()
+  if(vcpkg_no_avutil_target AND TARGET FFmpeg::avutil)
+    target_link_libraries(FFmpeg::avutil INTERFACE PkgConfig::libmfx)
+  endif()
+endif()
+
+set(FFMPEG_LIBRARY ${FFMPEG_LIBRARIES})
+
+set(CMAKE_MODULE_PATH ${FFMPEG_PREV_MODULE_PATH})
+
+unset(vcpkg_no_avformat_target)
+unset(vcpkg_no_avcodec_target)
+unset(vcpkg_no_avutil_target)