feat: lint and format tests in CI

Only src/ was covered, which is why it stayed clean while tests/ drifted to 38
findings. migrations/ stays out: its alembic template emits unused imports, so
every generated revision would fail the gate.

.gitea/workflows/ci.yml

@@ -37,10 +37,10 @@ jobs:
         run: uv sync --locked
 
       - name: Format
-        run: uv run ruff format --check src/
+        run: uv run ruff format --check src/ tests/
 
       - name: Lint
-        run: uv run ruff check src/
+        run: uv run ruff check src/ tests/
 
       # pytest-databases starts a throwaway PostgreSQL container, so this needs a working
       # Docker daemon on the runner — the same requirement the release workflow has.

.gitea/workflows/release.yml

@@ -42,8 +42,8 @@ jobs:
         working-directory: backend
         run: |
           uv sync --locked
-          uv run ruff format --check src/
-          uv run ruff check src/
+          uv run ruff format --check src/ tests/
+          uv run ruff check src/ tests/
           uv run pytest tests/ -q
 
       - uses: actions/setup-node@v4