refactor: migrate CI/CD workflows from GitHub Actions to Gitea Actions and remove legacy workflows

.gitea/workflows/ci.yml

@@ -0,0 +1,57 @@
+name: CI
+
+on:
+  pull_request:
+    branches: ["develop"]
+
+jobs:
+  backend-test:
+    name: Backend Tests
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: backend
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v4
+        with:
+          java-version: "21"
+          distribution: temurin
+          cache: gradle
+
+      - name: Make Gradle wrapper executable
+        run: chmod +x gradlew
+
+      - name: Run tests
+        run: ./gradlew test --no-daemon
+
+      - name: Upload test results
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: backend-test-results
+          path: backend/build/reports/tests/
+
+  frontend-test:
+    name: Frontend Tests
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: frontend
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Node 20
+        uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+          cache: npm
+          cache-dependency-path: frontend/package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run tests
+        run: npm run test