diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 18a60391b30..2b65eb5a9fb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -524,7 +524,9 @@ jobs:
       - name: Cache dist build
         uses: actions/cache@v5
         with:
-          path: dist/
+          path: |
+            dist/
+            dist-runtime/
           key: ${{ runner.os }}-dist-build-${{ github.sha }}
 
       - name: Upload A2UI bundle artifact
@@ -984,7 +986,9 @@ jobs:
         id: checks-dist-cache
         uses: actions/cache@v5
         with:
-          path: dist/
+          path: |
+            dist/
+            dist-runtime/
           key: ${{ runner.os }}-dist-build-${{ github.sha }}
 
       - name: Verify dist cache
@@ -1295,7 +1299,9 @@ jobs:
         id: dist-cache
         uses: actions/cache@v5
         with:
-          path: dist/
+          path: |
+            dist/
+            dist-runtime/
           key: ${{ runner.os }}-dist-build-${{ github.sha }}
 
       - name: Verify dist cache
@@ -1619,8 +1625,6 @@ jobs:
             group: extension-bundled
           - check_name: check-additional-extension-package-boundary
             group: extension-package-boundary
-          - check_name: check-additional-runtime-topology-gateway
-            group: runtime-topology-gateway
           - check_name: check-additional-runtime-topology-architecture
             group: runtime-topology-architecture
     steps:
@@ -1756,12 +1760,6 @@ jobs:
               run_check "test:extensions:package-boundary:compile" pnpm run test:extensions:package-boundary:compile
               run_check "test:extensions:package-boundary:canary" pnpm run test:extensions:package-boundary:canary
               ;;
-            runtime-topology-gateway)
-              if [ "$RUN_CONTROL_UI_I18N" = "true" ]; then
-                run_check "ui:i18n:check" pnpm ui:i18n:check
-              fi
-              run_check "gateway-watch-regression" pnpm test:gateway:watch-regression
-              ;;
             runtime-topology-architecture)
               run_check "check:architecture" pnpm check:architecture
               ;;
@@ -1773,8 +1771,92 @@ jobs:
 
           exit "$failures"
 
+  check-additional-runtime-topology-gateway:
+    permissions:
+      contents: read
+    name: "check-additional-runtime-topology-gateway"
+    needs: [preflight, build-artifacts]
+    if: ${{ !cancelled() && always() && needs.preflight.outputs.run_check_additional == 'true' && needs.build-artifacts.result == 'success' }}
+    runs-on: ubuntu-24.04
+    timeout-minutes: 20
+    steps:
+      - name: Checkout
+        shell: bash
+        env:
+          CHECKOUT_REPO: ${{ github.repository }}
+          CHECKOUT_SHA: ${{ github.sha }}
+          CHECKOUT_TOKEN: ${{ github.token }}
+        run: |
+          set -euo pipefail
+
+          workdir="$GITHUB_WORKSPACE"
+          auth_header="$(printf 'x-access-token:%s' "$CHECKOUT_TOKEN" | base64 | tr -d '\n')"
+
+          reset_checkout_dir() {
+            mkdir -p "$workdir"
+            find "$workdir" -mindepth 1 -maxdepth 1 -exec rm -rf {} +
+          }
+
+          checkout_attempt() {
+            local attempt="$1"
+
+            reset_checkout_dir
+            git init "$workdir" >/dev/null
+            git config --global --add safe.directory "$workdir"
+            git -C "$workdir" remote add origin "https://github.com/${CHECKOUT_REPO}"
+            git -C "$workdir" config gc.auto 0
+
+            timeout --signal=TERM 30s git -C "$workdir" \
+              -c protocol.version=2 \
+              -c "http.https://github.com/.extraheader=AUTHORIZATION: basic ${auth_header}" \
+              fetch --no-tags --prune --no-recurse-submodules --depth=1 origin \
+              "+${CHECKOUT_SHA}:refs/remotes/origin/ci-target" || return 1
+
+            git -C "$workdir" checkout --force --detach "$CHECKOUT_SHA" || return 1
+            test -f "$workdir/.github/actions/setup-node-env/action.yml" || return 1
+            echo "checkout attempt ${attempt}/2 succeeded"
+          }
+
+          for attempt in 1 2; do
+            if checkout_attempt "$attempt"; then
+              exit 0
+            fi
+            echo "checkout attempt ${attempt}/2 failed"
+            sleep $((attempt * 5))
+          done
+
+          echo "checkout failed after 2 attempts" >&2
+          exit 1
+
+      - name: Setup Node environment
+        uses: ./.github/actions/setup-node-env
+        with:
+          install-bun: "false"
+
+      - name: Restore dist cache
+        id: dist-cache
+        uses: actions/cache@v5
+        with:
+          path: |
+            dist/
+            dist-runtime/
+          key: ${{ runner.os }}-dist-build-${{ github.sha }}
+
+      - name: Verify dist cache
+        if: steps.dist-cache.outputs.cache-hit != 'true'
+        run: |
+          echo "Missing same-run dist cache for ${RUNNER_OS}-dist-build-${GITHUB_SHA}" >&2
+          exit 1
+
+      - name: Check Control UI i18n
+        if: needs.preflight.outputs.run_control_ui_i18n == 'true'
+        run: pnpm ui:i18n:check
+
+      - name: Run gateway watch regression
+        run: node scripts/check-gateway-watch-regression.mjs --skip-build
+
       - name: Upload gateway watch regression artifacts
-        if: always() && matrix.group == 'runtime-topology-gateway'
+        if: always()
         uses: actions/upload-artifact@v7
         with:
           name: gateway-watch-regression
@@ -1785,7 +1867,7 @@ jobs:
     permissions:
       contents: read
     name: "check-additional"
-    needs: [preflight, check-additional-shard]
+    needs: [preflight, check-additional-shard, check-additional-runtime-topology-gateway]
     if: ${{ !cancelled() && always() && needs.preflight.outputs.run_check_additional == 'true' }}
     runs-on: ubuntu-24.04
     timeout-minutes: 5
@@ -1793,11 +1875,16 @@ jobs:
       - name: Verify additional check shards
         env:
           SHARD_RESULT: ${{ needs.check-additional-shard.result }}
+          GATEWAY_RESULT: ${{ needs.check-additional-runtime-topology-gateway.result }}
         run: |
           if [ "$SHARD_RESULT" != "success" ]; then
             echo "Additional check shards failed: $SHARD_RESULT" >&2
             exit 1
           fi
+          if [ "$GATEWAY_RESULT" != "success" ]; then
+            echo "Gateway topology check failed: $GATEWAY_RESULT" >&2
+            exit 1
+          fi
 
   build-smoke:
     permissions:
diff --git a/docs/ci.md b/docs/ci.md
index c6e53fb349d..b7d65b9b317 100644
--- a/docs/ci.md
+++ b/docs/ci.md
@@ -53,7 +53,7 @@ Local changed-lane logic lives in `scripts/changed-lanes.mjs` and is executed by
 
 On pushes, the `checks` matrix adds the push-only `compat-node22` lane. On pull requests, that lane is skipped and the matrix stays focused on the normal test/channel lanes.
 
-The slowest Node test families are split or balanced so each job stays small: channel contracts split registry and core coverage into six weighted shards total, bundled plugin tests balance across six extension workers, auto-reply runs as three balanced workers instead of six tiny workers, and agentic gateway/plugin configs are spread across the existing source-only agentic Node jobs instead of waiting on built artifacts. Broad browser, QA, media, and miscellaneous plugin tests use their dedicated Vitest configs instead of the shared plugin catch-all. The broad agents lane uses the shared Vitest file-parallel scheduler because it is import/scheduling dominated rather than owned by a single slow test file. `runtime-config` runs with the infra core-runtime shard to keep the shared runtime shard from owning the tail. `check-additional` keeps package-boundary compile/canary work together and separates it from runtime topology gateway/architecture work; the boundary guard shard runs its small independent guards concurrently inside one job, and the gateway watch regression uses the minimal `gatewayWatch` build profile instead of rebuilding the full CI artifact sidecar set.
+The slowest Node test families are split or balanced so each job stays small: channel contracts split registry and core coverage into six weighted shards total, bundled plugin tests balance across six extension workers, auto-reply runs as three balanced workers instead of six tiny workers, and agentic gateway/plugin configs are spread across the existing source-only agentic Node jobs instead of waiting on built artifacts. Broad browser, QA, media, and miscellaneous plugin tests use their dedicated Vitest configs instead of the shared plugin catch-all. The broad agents lane uses the shared Vitest file-parallel scheduler because it is import/scheduling dominated rather than owned by a single slow test file. `runtime-config` runs with the infra core-runtime shard to keep the shared runtime shard from owning the tail. `check-additional` keeps package-boundary compile/canary work together and separates runtime topology architecture from gateway watch coverage; the boundary guard shard runs its small independent guards concurrently inside one job, and the gateway watch regression reuses the same-run built `dist/` and `dist-runtime/` cache from `build-artifacts` so it measures watch stability without rebuilding runtime artifacts in its own worker.
 Android CI runs both `testPlayDebugUnitTest` and `testThirdPartyDebugUnitTest`, then builds the Play debug APK. The third-party flavor has no separate source set or manifest; its unit-test lane still compiles that flavor with the SMS/call-log BuildConfig flags, while avoiding a duplicate debug APK packaging job on every Android-relevant push.
 `extension-fast` is PR-only because push runs already execute the full bundled plugin shards. That keeps changed-plugin feedback for reviews without reserving an extra Blacksmith worker on `main` for coverage already present in `checks-node-extensions`.