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/aom/aom-uninitialized-pointer.diff

@@ -0,0 +1,13 @@
+diff --git a/build/cmake/aom_configure.cmake b/build/cmake/aom_configure.cmake
+index aaef2c310..5500ad4a3 100644
+--- a/build/cmake/aom_configure.cmake
++++ b/build/cmake/aom_configure.cmake
+@@ -309,6 +309,8 @@ if(MSVC)
+ 
+   # Disable MSVC warnings that suggest making code non-portable.
+   add_compiler_flag_if_supported("/wd4996")
++  # Disable MSVC warnings for potentially uninitialized local pointer variable.
++  add_compiler_flag_if_supported("/wd4703")
+   if(ENABLE_WERROR)
+     add_compiler_flag_if_supported("/WX")
+   endif()