Add Dart SDK tests to CI workflow

Add a new job to run Dart SDK tests in GitHub Actions. The job runs tests from the sdks/community/dart directory, excluding tests tagged with 'requires-server' to ensure CI runs complete successfully without external dependencies.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: mattsp1290

.github/workflows/test.yml

@@ -89,4 +89,25 @@ jobs:
 
     - name: Run tests
       working-directory: typescript-sdk
-      run: pnpm run test
+      run: pnpm run test
+
+  dart:
+    name: Dart SDK Tests
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up Dart
+      uses: dart-lang/setup-dart@v1
+      with:
+        sdk: stable
+
+    - name: Install dependencies
+      working-directory: sdks/community/dart
+      run: dart pub get
+
+    - name: Run tests
+      working-directory: sdks/community/dart
+      run: dart test --exclude-tags requires-server