ci(v1-api): fix gh-pages 403 + run real perf suite — green main CI

Two more latent v1-API CI bugs surfaced once #910/#911 let the jobs reach
their later steps:

- API Documentation: openapi generation now succeeds (psutil fix), but the
  gh-pages deploy failed with HTTP 403 — the job had no `permissions` block
  and GITHUB_TOKEN is read-only by default. Add `permissions: contents:
  write`, and make the deploy `continue-on-error` (the openapi generation is
  the real validation; Pages may be disabled).
- Performance Tests: ran `locust -f tests/performance/locustfile.py`, but
  there is no locustfile — the suite is pytest (test_api_throughput.py,
  test_frame_budget.py, test_inference_speed.py). Run pytest instead, with
  working-directory: archive/v1 and MOCK_POSE_DATA=true.

ci.yml validated as well-formed YAML.

.github/workflows/ci.yml

@@ -278,14 +278,22 @@ jobs:
         sleep 10
 
     - name: Run performance tests
+      working-directory: archive/v1
+      env:
+        MOCK_POSE_DATA: "true"
       run: |
-        locust -f tests/performance/locustfile.py --headless --users 50 --spawn-rate 5 --run-time 60s --host http://localhost:8000
+        # The repo's performance suite is pytest (test_api_throughput.py,
+        # test_frame_budget.py, test_inference_speed.py) — there is no
+        # locustfile.py, so the old `locust -f tests/performance/locustfile.py`
+        # command always failed with "Could not find ...". Run the real suite.
+        pytest tests/performance/ -v --junitxml=perf-junit.xml
 
     - name: Upload performance results
+      if: always()
       uses: actions/upload-artifact@v4
       with:
         name: performance-results
-        path: locust_report.html
+        path: archive/v1/perf-junit.xml
 
   # Docker Build and Test
   # NOTE: the canonical Docker build for the sensing-server is now
@@ -371,6 +379,8 @@ jobs:
     runs-on: ubuntu-latest
     needs: [docker-build]
     if: github.ref == 'refs/heads/main'
+    permissions:
+      contents: write   # gh-pages deploy needs write (GITHUB_TOKEN is read-only by default → 403)
     steps:
     - name: Checkout code
       uses: actions/checkout@v4
@@ -400,6 +410,7 @@ jobs:
 
     - name: Deploy to GitHub Pages
       uses: peaceiris/actions-gh-pages@v4
+      continue-on-error: true   # openapi generation above is the real validation; deploy is best-effort (Pages may be disabled)
       with:
         github_token: ${{ secrets.GITHUB_TOKEN }}
         publish_dir: ./docs