fix(ci): restore Linux E2E selection and split offline enrollment (#7843)

.github/workflows/ci.yml

@@ -259,9 +259,6 @@ jobs:
           } > artifacts/test-and-lint/doctest-diagnostics.txt
           exit "${status}"
 
-      - name: Check offline enrollment E2E root boundary
-        run: ./scripts/check_offline_enrollment_e2e.sh
-
       - name: Upload test reports and diagnostics
         if: always()
         uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6
@@ -296,6 +293,37 @@ jobs:
       - name: Run rebalance/decommission migration proofs
         run: ./scripts/check_migration_gate_count.sh
 
+  # This gate builds into a fresh target directory to isolate the E2E root.
+  # Give its cold build a separate budget from workspace tests and migration proofs.
+  offline-enrollment-e2e:
+    name: Offline Enrollment E2E Root Boundary
+    if: needs.classify-changes.outputs.mode == 'full' && (github.event_name != 'pull_request' || github.event.action != 'closed')
+    needs: [ quick-checks, classify-changes ]
+    runs-on: sm-standard-4
+    timeout-minutes: 60
+    env:
+      FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7
+        with:
+          persist-credentials: false
+
+      - name: Setup Rust environment
+        uses: ./.github/actions/setup
+        with:
+          rust-version: stable
+          cache-shared-key: ci-dev
+          cache-save-if: 'false'
+          install-build-packaging-tools: 'false'
+          install-test-tools: 'false'
+
+      - name: Protect Connect test home
+        run: chmod go-w "$(realpath "$HOME")"
+
+      - name: Check offline enrollment E2E root boundary
+        run: ./scripts/check_offline_enrollment_e2e.sh
+
   # Dedicated serial lane for the ILM / lifecycle integration tests. These tests
   # drive the object layer through process-global singletons (the GLOBAL_ENV
   # ECStore, the global tier-config manager, background-expiry workers) and bind
@@ -1190,6 +1218,7 @@ jobs:
       - typos
       - quick-checks
       - test-and-lint
+      - offline-enrollment-e2e
       - test-ilm-integration-serial
       - test-and-lint-rio-v2
       - connect-short-credential-boundary
@@ -1223,6 +1252,7 @@ jobs:
       - typos
       - quick-checks
       - test-and-lint
+      - offline-enrollment-e2e
       - test-ilm-integration-serial
       - test-and-lint-rio-v2
       - test-and-lint-protocols