ci: add GitHub Actions workflow with ruff and E2E tests

- Add CI workflow running Ruff lint/format checks
- Run full E2E cycle (Docker Compose + Playwright + tests)
- Refactor code formatting to satisfy Ruff (line breaks, readability)
- Use sys.executable in tests for interpreter-agnostic execution

https://chatgpt.com/share/694a7f81-d96c-800f-88cb-7b25b4cdfe1a

.github/workflows/ci.yml

@@ -0,0 +1,65 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  lint-and-e2e:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+          cache: "pip"
+
+      - name: Install system deps (curl)
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y curl
+
+      - name: Install Python deps
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e ".[e2e]"
+          pip install ruff
+
+      - name: Ruff
+        run: |
+          ruff check .
+          ruff format --check .
+
+      # Playwright needs browser binaries on the runner
+      - name: Install Playwright Chromium
+        run: |
+          python -m playwright install --with-deps chromium
+
+      # Run your full E2E cycle using the existing Makefile
+      - name: E2E (docker compose + installer + tests)
+        env:
+          MATOMO_URL: "http://127.0.0.1:8080"
+          MATOMO_ADMIN_USER: "administrator"
+          MATOMO_ADMIN_PASSWORD: "AdminSecret123!"
+          MATOMO_ADMIN_EMAIL: "administrator@example.org"
+          MATOMO_TOKEN_DESCRIPTION: "ci-token"
+        run: |
+          make e2e
+
+      # If E2E fails, this is helpful for debugging
+      - name: Docker logs (on failure)
+        if: failure()
+        run: |
+          docker compose -f tests/e2e/docker-compose.yml ps || true
+          docker compose -f tests/e2e/docker-compose.yml logs --no-color --tail=300 matomo || true
+          docker compose -f tests/e2e/docker-compose.yml logs --no-color --tail=300 db || true
+
+      - name: Cleanup (always)
+        if: always()
+        run: |
+          docker compose -f tests/e2e/docker-compose.yml down -v || true