Refactor CI workflow and remove example widget tests

Splits the build job in the CI workflow into separate jobs for cnativeapi and nativeapi examples, adding Android and iOS build steps. Removes default widget_test.dart files from all example and package example projects to clean up unused test files.

Author: lijy91

.github/workflows/ci.yml

@@ -80,8 +80,8 @@ jobs:
       - name: Run tests
         run: dart pub global run melos run test
 
-  build:
-    name: Build (${{ matrix.os }})
+  build_cnativeapi:
+    name: Build cnativeapi example (${{ matrix.os }})
     runs-on: ${{ matrix.os }}
     needs: [lint, test]
     strategy:
@@ -115,35 +115,108 @@ jobs:
       - name: Bootstrap melos
         run: dart pub global run melos bootstrap
 
-      - name: Build cnativeapi example Linux
+      - name: Setup Java for Android
+        if: matrix.os == 'ubuntu-latest'
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: '17'
+          
+      - name: Build cnativeapi example Android
         if: matrix.os == 'ubuntu-latest'
         run: |
           cd packages/cnativeapi/example
-          flutter build linux --release
+          flutter build apk --release
           
-      - name: Build nativeapi example Linux
+      - name: Build cnativeapi example Linux
         if: matrix.os == 'ubuntu-latest'
         run: |
-          cd packages/nativeapi/example
+          cd packages/cnativeapi/example
           flutter build linux --release
           
-      - name: Build cnativeapi example macOS
+      - name: Build cnativeapi example iOS
         if: matrix.os == 'macos-latest'
         run: |
           cd packages/cnativeapi/example
-          flutter build macos --release
+          flutter build ios --release --no-codesign
           
-      - name: Build nativeapi example macOS
+      - name: Build cnativeapi example macOS
         if: matrix.os == 'macos-latest'
         run: |
-          cd packages/nativeapi/example
+          cd packages/cnativeapi/example
           flutter build macos --release
           
       - name: Build cnativeapi example Windows
         if: matrix.os == 'windows-latest'
         run: |
           cd packages/cnativeapi/example
           flutter build windows --release
+
+  build_nativeapi:
+    name: Build nativeapi example (${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    needs: [lint, test]
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        
+      - name: Setup Flutter
+        uses: subosito/flutter-action@v2
+        with:
+          flutter-version: '3.38.7'
+          channel: 'stable'
+          cache: true
+          
+      - name: Install melos
+        run: dart pub global activate melos
+        
+      - name: Add melos to PATH
+        shell: bash
+        run: |
+          if [[ "$RUNNER_OS" == "Windows" ]]; then
+            echo "$USERPROFILE/.pub-cache/bin" >> $GITHUB_PATH
+          else
+            echo "$HOME/.pub-cache/bin" >> $GITHUB_PATH
+          fi
+        
+      - name: Bootstrap melos
+        run: dart pub global run melos bootstrap
+        
+      - name: Setup Java for Android
+        if: matrix.os == 'ubuntu-latest'
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: '17'
+          
+      - name: Build nativeapi example Android
+        if: matrix.os == 'ubuntu-latest'
+        run: |
+          cd packages/nativeapi/example
+          flutter build apk --release
+          
+      - name: Build nativeapi example Linux
+        if: matrix.os == 'ubuntu-latest'
+        run: |
+          cd packages/nativeapi/example
+          flutter build linux --release
+          
+      - name: Build nativeapi example iOS
+        if: matrix.os == 'macos-latest'
+        run: |
+          cd packages/nativeapi/example
+          flutter build ios --release --no-codesign
+          
+      - name: Build nativeapi example macOS
+        if: matrix.os == 'macos-latest'
+        run: |
+          cd packages/nativeapi/example
+          flutter build macos --release
           
       - name: Build nativeapi example Windows
         if: matrix.os == 'windows-latest'