Switch coverage reporting from Codecov to Coveralls

.github/workflows/ci.yml

@@ -179,19 +179,15 @@ jobs:
             --dev \
             --frozen \
             pytest
-      - name: Upload backend test results to Codecov
+      - name: Upload backend coverage to Coveralls
         if: always()
-        uses: codecov/test-results-action@v1
+        uses: coverallsapp/github-action@v2
         with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          flags: backend-python-${{ matrix.python-version }}
-          files: junit.xml
-      - name: Upload backend coverage to Codecov
-        uses: codecov/codecov-action@v5
-        with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          flags: backend-python-${{ matrix.python-version }}
-          files: coverage.xml
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          file: coverage.xml
+          format: cobertura
+          flag-name: backend-python-${{ matrix.python-version }}
+          parallel: true
       - name: Stop containers
         if: always()
         run: |
@@ -261,19 +257,28 @@ jobs:
         run: cd src-ui && pnpm run lint
       - name: Run Jest unit tests
         run: cd src-ui && pnpm run test --max-workers=2 --shard=${{ matrix.shard-index }}/${{ matrix.shard-count }}
-      - name: Upload frontend test results to Codecov
-        uses: codecov/test-results-action@v1
+      - name: Upload frontend coverage to Coveralls
         if: always()
+        uses: coverallsapp/github-action@v2
         with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          flags: frontend-node-${{ matrix.node-version }}
-          directory: src-ui/
-      - name: Upload frontend coverage to Codecov
-        uses: codecov/codecov-action@v5
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          file: src-ui/coverage/lcov.info
+          format: lcov
+          flag-name: frontend-node-${{ matrix.node-version }}-shard-${{ matrix.shard-index }}
+          parallel: true
+  coveralls-finish:
+    name: Finalize Coveralls
+    runs-on: ubuntu-24.04
+    needs:
+      - tests-backend
+      - tests-frontend
+    if: ${{ always() }}
+    steps:
+      - name: Mark Coveralls jobs complete
+        uses: coverallsapp/github-action@v2
         with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          flags: frontend-node-${{ matrix.node-version }}
-          directory: src-ui/coverage/
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          parallel-finished: true
   tests-frontend-e2e:
     name: "Frontend E2E Tests (Node ${{ matrix.node-version }} - ${{ matrix.shard-index }}/${{ matrix.shard-count }})"
     runs-on: ubuntu-24.04
@@ -351,8 +356,6 @@ jobs:
       - name: Re-link Angular cli
         run: cd src-ui && pnpm link @angular/cli
       - name: Build frontend and upload analysis
-        env:
-          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
         run: cd src-ui && pnpm run build --configuration=production
   build-docker-image:
     name: Build Docker image for ${{ github.ref_name }}