Backend project initialized

Co-authored-by: Jarno Kiesiläinen <jarnokie@gmail.com>
Co-committed-by: Jarno Kiesiläinen <jarnokie@gmail.com>

.gitea/workflows/backend-ci.yml

@@ -0,0 +1,44 @@
+name: Backend CI
+
+on:
+  push:
+    branches: [ main, develop ]
+    paths:
+      - 'backend/**'
+  pull_request:
+    branches: [ main, develop ]
+    paths:
+      - 'backend/**'
+
+jobs:
+  test:
+    name: Run Maven Tests
+    runs-on: ubuntu-latest
+    
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      
+    - name: Set up JDK 21
+      uses: actions/setup-java@v4
+      with:
+        java-version: '21'
+        distribution: 'temurin'
+        cache: 'maven'
+
+    - name: Set up Maven
+      uses: stCarolas/setup-maven@v5
+      with:
+        maven-version: '3.6.3'
+        
+    - name: Run Maven tests
+      working-directory: ./backend
+      run: mvn test
+      
+    - name: Upload test results
+      uses: actions/upload-artifact@v3
+      if: always()
+      with:
+        name: backend-test-results
+        path: backend/target/surefire-reports/
+        retention-days: 7