ci(adcp): add storyboard CI job for seller_agent.py compliance checks

.github/workflows/ci.yml

@@ -330,3 +330,89 @@ jobs:
             echo "  Numbered-variant class-name churn is expected; the semantic"
             echo "  alias tests and drift-version-pin test guard the real surface."
           fi
+
+  storyboard:
+    name: AdCP storyboard runner — examples/seller_agent.py
+    runs-on: ubuntu-latest
+    # Non-blocking until seller-agent content gaps in #304 are resolved.
+    # Promote to required once overall_status: passing and controller_detected: true.
+    continue-on-error: true
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python 3.12
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+
+      - name: Set up Node 22
+        uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e ".[dev]"
+
+      - name: Start seller agent
+        run: |
+          ADCP_PORT=3001 python examples/seller_agent.py &
+          AGENT_PID=$!
+          for i in $(seq 1 60); do
+            # Any HTTP response (including 405 on GET to a POST-only endpoint)
+            # means the server is up and accepting connections.
+            HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" --max-time 1 \
+              http://127.0.0.1:3001/mcp 2>/dev/null || echo "000")
+            if [ "$HTTP_CODE" != "000" ]; then
+              echo "Seller agent ready (HTTP ${HTTP_CODE}, pid ${AGENT_PID})"
+              break
+            fi
+            if ! kill -0 "$AGENT_PID" 2>/dev/null; then
+              echo "Seller agent process died during startup"
+              exit 1
+            fi
+            if [ "$i" -eq 60 ]; then
+              echo "Seller agent failed to start within 30s"
+              kill "$AGENT_PID" 2>/dev/null || true
+              exit 1
+            fi
+            sleep 0.5
+          done
+
+      - name: Run storyboard suite
+        timeout-minutes: 5
+        # @adcp/client@latest is intentionally unpinned — this is AdCP's own CI
+        # running AdCP's own canonical runner. Tracking latest surfaces protocol
+        # drift as soon as it ships, which is the point of this job.
+        run: |
+          npx -y -p @adcp/client@latest adcp storyboard run \
+            http://127.0.0.1:3001/mcp media_buy_seller \
+            --json --allow-http \
+            > storyboard-result.json
+
+      - name: Assert pass
+        run: |
+          python -c "
+          import json, sys, pathlib
+          p = pathlib.Path('storyboard-result.json')
+          if not p.exists() or p.stat().st_size == 0:
+              print('storyboard-result.json missing or empty — runner produced no output')
+              sys.exit(1)
+          with p.open() as f:
+              d = json.load(f)
+          if d.get('overall_status') != 'passing':
+              print(json.dumps(d, indent=2))
+              sys.exit(1)
+          if not d.get('controller_detected'):
+              print('controller_detected was false; check DemoStore overrides (see #304)')
+              sys.exit(1)
+          "
+
+      - if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: storyboard-result-${{ github.run_attempt }}
+          path: storyboard-result.json
+          if-no-files-found: warn