US09-05: Automate Documentation Acceptance

.gitea/workflows/test.yml

@@ -101,3 +101,39 @@ jobs:
         with:
           name: container-gate-${{ gitea.sha }}
           path: gate-evidence
+
+  # The manuals, checked against the application they describe (US09-05). Runs on
+  # every pull request as well as `main`: documentation drifts by the same commits
+  # that change behaviour, and telling the author while the change is still open is
+  # the only time the fix is cheap.
+  documentation:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - name: Install the application and its test dependencies
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install -e '.[test]'
+          python -m playwright install --with-deps chromium
+
+      - name: Documentation gate
+        # One command: every phase_i check, offline and in the browser, with the
+        # evidence retained. It accepts no skip — a check that did not run is a page
+        # nobody compared with the code.
+        env:
+          PHOTO_PIPELINE_DATA_DIR: ${{ gitea.workspace }}/docs-gate-data
+        run: python -m photo_pipeline docs-gate --output docs-evidence
+
+      - name: Keep the evidence
+        if: always()
+        uses: actions/upload-artifact@v3
+        with:
+          name: docs-gate-${{ gitea.sha }}
+          path: docs-evidence