add dart macos CLI example

dart_filament/examples/cli_macos/pubspec.yaml

@@ -0,0 +1,20 @@
+name: example_cli
+description: A sample command-line application.
+version: 1.0.0
+# repository: https://github.com/my_org/my_repo
+
+environment:
+  sdk: ^3.3.0
+
+# Add regular dependencies here.
+dependencies:
+  dart_filament:
+    path: ../../
+  ffi:
+
+dev_dependencies:
+  ffigen: ^11.0.0
+  lints: ^3.0.0
+  test: ^1.24.0
+  native_assets_cli: ^0.5.0
+  native_toolchain_c: ^0.4.0