Add Flutter/Dart CI workflow

.github/workflows/flutter-ci.yml

@@ -0,0 +1,68 @@
+name: Flutter CI
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - 'flutter_module/**'
+      - 'flutter_sharp/**'
+      - '.github/workflows/flutter-ci.yml'
+  pull_request:
+    branches: [main]
+    paths:
+      - 'flutter_module/**'
+      - 'flutter_sharp/**'
+      - '.github/workflows/flutter-ci.yml'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: stable
+          cache: true
+
+      - name: Get dependencies
+        working-directory: flutter_module
+        run: flutter pub get
+
+      - name: Analyze
+        working-directory: flutter_module
+        run: flutter analyze
+
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: stable
+          cache: true
+
+      - name: Get dependencies
+        working-directory: flutter_module
+        run: flutter pub get
+
+      - name: Run tests
+        working-directory: flutter_module
+        run: flutter test
+
+  format-check:
+    name: Format Check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: stable
+          cache: true
+
+      - name: Check formatting
+        run: dart format --output=none --set-exit-if-changed flutter_module/lib/