feat(benchmark): latency benchmark suite with CI gate (#78)

.github/workflows/ci.yml

@@ -46,3 +46,28 @@ jobs:
         uses: codecov/codecov-action@v6
         with:
           fail_ci_if_error: false
+
+  benchmark:
+    runs-on: ubuntu-latest
+    needs: test
+    if: github.ref == 'refs/heads/main'
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/setup-python@v6
+        with:
+          python-version: "3.12"
+
+      - name: Install dependencies
+        run: python -m pip install --upgrade pip setuptools && pip install -e ".[dev]"
+
+      - name: Run benchmark (software-only, CI gate p99 < 5ms)
+        run: python -m cmcp_gateway.benchmarks --provider software-only --calls 10000 --out benchmarks/
+
+      - name: Upload benchmark results
+        uses: actions/upload-artifact@v4
+        with:
+          name: benchmark-results
+          path: benchmarks/
+          if-no-files-found: warn

benchmarks/.gitkeep

@@ -0,0 +1 @@
+{"note": "benchmark results committed by CI"}