Implement comprehensive frontend integration testing with Playwright

- Add Playwright E2E testing framework with cross-browser support (Chrome, Firefox)
- Create authentication helpers for CalDAV server integration
- Implement calendar interaction helpers with event creation, drag-and-drop, and view switching
- Add comprehensive drag-and-drop test suite with event cleanup
- Configure CI/CD integration with Gitea Actions for headless testing
- Support both local development and CI environments with proper dependency management
- Include video recording, screenshots, and HTML reporting for test debugging
- Handle Firefox-specific timing and interaction challenges with force clicks and timeouts

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

Co-Authored-By: Claude <noreply@anthropic.com>

.gitea/workflows/integration-tests.yml

@@ -0,0 +1,133 @@
+name: Integration Tests
+
+on:
+  push:
+    branches: [ main, feature/integration-testing ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  e2e-tests:
+    runs-on: ubuntu-latest
+    
+    services:
+      # Backend service for testing
+      backend:
+        image: ubuntu-latest
+        ports:
+          - 3000:3000
+    
+    steps:
+    - uses: actions/checkout@v3
+    
+    - name: Set up Rust
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: stable
+        override: true
+        components: rustfmt, clippy
+    
+    - name: Set up Node.js
+      uses: actions/setup-node@v3
+      with:
+        node-version: '18'
+        cache: 'npm'
+        cache-dependency-path: frontend/e2e/package-lock.json
+    
+    - name: Install Trunk
+      uses: jetli/trunk-action@v0.4.0
+      with:
+        version: 'latest'
+    
+    - name: Install wasm32 target
+      run: rustup target add wasm32-unknown-unknown
+    
+    - name: Build backend
+      run: |
+        cd backend
+        cargo build --release
+    
+    - name: Build frontend
+      run: |
+        trunk build --release
+    
+    - name: Install E2E test dependencies
+      run: |
+        cd frontend/e2e
+        npm ci
+        npx playwright install chromium firefox
+        # Install system dependencies for Ubuntu runner
+        sudo apt-get update && sudo apt-get install -y \
+          libnss3 libatk-bridge2.0-0 libdrm2 libgtk-3-0 \
+          libgbm1 libasound2
+    
+    - name: Start backend server
+      run: |
+        cd backend
+        cargo run --release &
+        # Wait for server to start
+        sleep 10
+        curl -f http://localhost:3000/health || exit 1
+      env:
+        CI: true
+    
+    - name: Start frontend server
+      run: |
+        trunk serve --release --address 0.0.0.0 &
+        # Wait for frontend to start
+        sleep 10
+        curl -f http://localhost:8080 || exit 1
+      env:
+        CI: true
+    
+    - name: Run E2E tests
+      run: |
+        cd frontend/e2e
+        npx playwright test --project=chromium --project=firefox
+      env:
+        CI: true
+        TEST_CALDAV_SERVER: https://baikal.rcjohnstone.com/dav.php/
+        TEST_CALDAV_USERNAME: test
+        TEST_CALDAV_PASSWORD: I0W?7`|Cs6tA`s
+    
+    - name: Upload test results
+      uses: actions/upload-artifact@v3
+      if: always()
+      with:
+        name: playwright-report
+        path: frontend/e2e/playwright-report/
+        retention-days: 30
+
+  unit-tests:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/checkout@v3
+    
+    - name: Set up Rust
+      uses: actions-rs/toolchain@v1
+      with:
+        toolchain: stable
+        override: true
+        components: rustfmt, clippy
+    
+    - name: Install wasm32 target
+      run: rustup target add wasm32-unknown-unknown
+    
+    - name: Install wasm-pack
+      run: curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+    
+    - name: Run frontend unit tests
+      run: |
+        cd frontend
+        wasm-pack test --headless --chrome --firefox
+    
+    - name: Run backend unit tests
+      run: |
+        cd backend
+        cargo test
+    
+    - name: Run calendar-models tests
+      run: |
+        cd calendar-models
+        cargo test --features wasm