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/pacman_install

@@ -0,0 +1,47 @@
+# arg 1:  the new package version
+#pre_install() {
+#}
+
+# arg 1:  the new package version
+post_install() {
+	# do something here
+	cp /usr/share/rustdesk/files/rustdesk.service /etc/systemd/system/rustdesk.service
+	cp /usr/share/rustdesk/files/rustdesk.desktop /usr/share/applications/
+	cp /usr/share/rustdesk/files/rustdesk-link.desktop /usr/share/applications/
+	systemctl daemon-reload
+	systemctl enable rustdesk
+	systemctl start rustdesk
+	update-desktop-database
+}
+
+# arg 1:  the new package version
+# arg 2:  the old package version
+pre_upgrade() {
+    systemctl stop rustdesk || true
+}
+
+# arg 1:  the new package version
+# arg 2:  the old package version
+post_upgrade() {
+	cp /usr/share/rustdesk/files/rustdesk.service /etc/systemd/system/rustdesk.service
+	cp /usr/share/rustdesk/files/rustdesk.desktop /usr/share/applications/
+	cp /usr/share/rustdesk/files/rustdesk-link.desktop /usr/share/applications/
+	systemctl daemon-reload
+	systemctl enable rustdesk
+	systemctl start rustdesk
+	update-desktop-database
+}
+
+# arg 1:  the old package version
+pre_remove() {
+	systemctl stop rustdesk || true
+	systemctl disable rustdesk || true
+	rm /etc/systemd/system/rustdesk.service || true
+}
+
+# arg 1:  the old package version
+post_remove() {
+	rm /usr/share/applications/rustdesk.desktop || true
+	rm /usr/share/applications/rustdesk-link.desktop || true
+	update-desktop-database
+}