diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 4b6ad8f81..3045d8939 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -247,12 +247,56 @@ jobs:
           if-no-files-found: ignore
 
   ui-regression:
-    name: Advisory UI regression
+    name: UI regression
+    needs: changes
+    if: needs.changes.outputs.ui_changed == 'true'
+    runs-on: ubuntu-24.04
+    timeout-minutes: 45
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v5
+        with:
+          node-version-file: ".nvmrc"
+          cache: npm
+          cache-dependency-path: package-lock.json
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Restore Chromium browser cache
+        uses: actions/cache@v6
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-chromium-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
+
+      - name: Install Chromium browser
+        run: npx playwright install --with-deps chromium
+
+      - name: Chromium stable regression suite
+        run: npm run test:e2e:regression
+
+      - name: Upload UI regression diagnostics
+        if: failure()
+        uses: actions/upload-artifact@v7
+        with:
+          name: ui-regression-diagnostics-${{ github.run_id }}
+          path: |
+            test-results/
+            playwright-report/
+          if-no-files-found: ignore
+
+  ui-quarantine:
+    name: Advisory quarantined UI tests
     needs: changes
     if: github.event_name == 'pull_request' && needs.changes.outputs.ui_changed == 'true'
     continue-on-error: true
     runs-on: ubuntu-24.04
-    timeout-minutes: 45
+    timeout-minutes: 30
     steps:
       - name: Checkout
         uses: actions/checkout@v6
@@ -278,14 +322,14 @@ jobs:
       - name: Install Chromium browser
         run: npx playwright install --with-deps chromium
 
-      - name: Chromium advisory regression
-        run: npm run test:e2e:advisory
+      - name: Chromium quarantined tests (advisory)
+        run: npm run test:e2e:quarantine
 
-      - name: Upload advisory UI diagnostics
+      - name: Upload quarantine diagnostics
         if: failure()
         uses: actions/upload-artifact@v7
         with:
-          name: advisory-ui-diagnostics-${{ github.run_id }}
+          name: quarantine-ui-diagnostics-${{ github.run_id }}
           path: |
             test-results/
             playwright-report/
@@ -341,7 +385,7 @@ jobs:
 
   pr-required:
     name: PR required
-    needs: [changes, static-pr, safety, coverage, build, ui-critical, db-reset-verify]
+    needs: [changes, static-pr, safety, coverage, build, ui-critical, ui-regression, db-reset-verify]
     if: always()
     runs-on: ubuntu-24.04
     timeout-minutes: 5
@@ -359,6 +403,7 @@ jobs:
           COVERAGE_RESULT: ${{ needs.coverage.result }}
           BUILD_RESULT: ${{ needs.build.result }}
           UI_RESULT: ${{ needs.ui-critical.result }}
+          UI_REGRESSION_RESULT: ${{ needs.ui-regression.result }}
           DB_RESULT: ${{ needs.db-reset-verify.result }}
         run: |
           set -euo pipefail
@@ -404,8 +449,10 @@ jobs:
 
           if [ "$UI_CHANGED" = "true" ]; then
             require_success "ui-critical" "$UI_RESULT"
+            require_success "ui-regression" "$UI_REGRESSION_RESULT"
           else
             require_skipped_or_success "ui-critical" "$UI_RESULT"
+            require_skipped_or_success "ui-regression" "$UI_REGRESSION_RESULT"
           fi
 
           if [ "$DB_CHANGED" = "true" ]; then
diff --git a/docs/process-hardening.md b/docs/process-hardening.md
index 7091dae4e..3992c67a8 100644
--- a/docs/process-hardening.md
+++ b/docs/process-hardening.md
@@ -131,10 +131,11 @@ passes `p_worker_id`. Ordered apply steps, R17 manual `CONCURRENTLY` index, and
 
 ## PR merge gate: risk-scoped CI + required aggregate (2026-07-10)
 
-- CI now has one always-reporting required aggregate: `CI / PR required`. The aggregate depends on `changes`, `static-pr`, `safety`, `coverage`, `build`, `ui-critical`, and `db-reset-verify`, then enforces only the jobs whose scopes apply.
+- CI now has one always-reporting required aggregate: `CI / PR required`. The aggregate depends on `changes`, `static-pr`, `safety`, `coverage`, `build`, `ui-critical`, `ui-regression`, and `db-reset-verify`, then enforces only the jobs whose scopes apply.
 - `static-pr` is the deterministic baseline for every PR: runtime, action pin check, CI scope self-test, format, lint, typecheck, and unit tests. Coverage, build, safety/config, critical UI, production-backed offline RAG preflight, and migration replay are independent jobs so reruns stay focused. Coverage is limited to `src`/test changes; process-only changes do not trigger builds.
 - `db-reset-verify` is path-scoped to Supabase migrations/schema/config and database-access code. Do not also require an external Supabase Preview replay unless the repo owner intentionally wants duplicate migration replay.
-- `ui-critical` is path-scoped to UI/routing/styling/browser-facing changes and runs only the `@critical` Chromium smoke subset. `ui-regression` runs the remaining Chromium cases on UI pull requests as advisory feedback and is deliberately excluded from `pr-required`. The full browser matrix remains main/release/manual/scheduled.
+- `ui-critical` is path-scoped to UI/routing/styling/browser-facing changes and runs only the `@critical` Chromium smoke subset. `ui-regression` (2026-07-13 audit, finding 8) runs the remaining stable Chromium cases via `test:e2e:regression` (`--grep-invert "@critical|@quarantine"`) and is **merge-blocking** through `pr-required` on UI changes. Genuinely flaky specs are tagged `@quarantine` and run in the advisory `ui-quarantine` job (`test:e2e:quarantine`, `--pass-with-no-tests`); fix and untag them rather than letting the quarantine grow. The full browser matrix remains main/release/manual/scheduled.
+- 2026-07-13 flip-day triage: the whole 142-test regression set was green locally except one stale `/privacy` heading assertion (fixed — the page title is "Privacy & data handling" since the footer simplification) and three cold-dev-server timing timeouts that pass on a warmed server and have no CI failure history (`ui-tools` mode-home centering `:462`, differentials comparison wiring `:1367`, `ui-universal-search` grouped-result navigation `:102`). Watch those three; if one flakes in CI, tag it `@quarantine` rather than reverting the gate.
 - Branch protection for `main` should require `CI / PR required` and `Secret Scan / Gitleaks`. Keep `SAST / Semgrep` required only if the repository owner accepts its external-rule/network dependency as part of the normal merge gate. Do not require path-filtered or scheduled/manual contexts such as `CI / Unit coverage`, `CI / Critical UI smoke`, `CI / Migration replay`, `Docker image build / app-image`, `Docker image build / worker-image`, `CI / release-browser-matrix`, `Eval Canary`, or `Live drift check`; they can be skipped on ordinary PRs and would leave branches stuck at "Expected - Waiting for status to be reported."
 
 ## CSS cascade layering (2026-07-02)
diff --git a/package.json b/package.json
index a215e063c..79758e855 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,8 @@
     "test:e2e:all": "node scripts/run-playwright.mjs",
     "test:e2e:accessibility": "node scripts/run-playwright.mjs tests/ui-accessibility.spec.ts --project=chromium",
     "test:e2e:critical": "node scripts/run-playwright.mjs --project=chromium --grep @critical",
-    "test:e2e:advisory": "node scripts/run-playwright.mjs --project=chromium --grep-invert @critical",
+    "test:e2e:regression": "node scripts/run-playwright.mjs --project=chromium --grep-invert \"@critical|@quarantine\"",
+    "test:e2e:quarantine": "node scripts/run-playwright.mjs --project=chromium --grep @quarantine --pass-with-no-tests",
     "test:e2e:chromium": "node scripts/run-playwright.mjs --project=chromium",
     "test:e2e:visual": "node scripts/run-playwright.mjs --config=playwright.visual.config.ts",
     "verify:cheap": "npm run check:runtime && npm run check:github-actions && npm run sitemap:check && npm run brand:check && npm run check:type-scale && npm run check:icon-scale && npm run lint && npm run typecheck && npm run test",