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/mfx-dispatch/vcpkg.json

@@ -0,0 +1,16 @@
+{
+  "name": "mfx-dispatch",
+  "version": "1.35.1",
+  "port-version": 5,
+  "description": "Open source Intel media sdk dispatcher",
+  "homepage": "https://github.com/lu-zero/mfx_dispatch",
+  "license": "BSD-3-Clause",
+  "supports": "((x86 | x64) & (android | linux)) | (windows & !uwp)",
+  "dependencies": [
+    {
+    "name": "vcpkg-cmake",
+    "host": true,
+    "platform": "windows & !mingw"
+    }
+  ]
+}