feat(2): Q1.2 — n8n Phase-2 parity + functional + robust install (full e2e green)

- tests/n8n/PARITY.md: parity table (health_check ported) + 2 recipe-specific
  functional tests with rationale + data-integrity section pointing to
  Phase-1d/1e lifecycle overlays.
- tests/n8n/functional/test_health_check.py: parity port of
  recipe-info/n8n/tests/health_check.py — SOURCE comment.
- tests/n8n/functional/test_rest_settings.py: NEW recipe-specific — polls
  /rest/settings until response is application/json (not the 'n8n is starting
  up' SPA placeholder); asserts known n8n public-settings keys
  (userManagement/defaultLocale/authCookie) in the 'data' envelope. Proves the
  editor SPA's primary API contract is intact.
- tests/n8n/functional/test_login_state.py: NEW recipe-specific — polls
  /rest/login until response is JSON; proves the user-management/auth subsystem
  initialized on top of the public-settings layer.
- tests/n8n/test_install.py: install overlay's Playwright now polls page.goto
  until status==200 (n8n's / route can return 404 briefly while the SPA route
  registers on top of /healthz=200). Bounded poll, no bare sleep, raise on
  persistent failure — same robustness pattern as Phase-1e exec_in_app.

Cold-verifiable on cc-ci (log /root/ccci-q1-n8n-r3.log):
  RECIPE=n8n cc-ci-run runner/run_recipe_ci.py
  all 5 stages PASS, deploy-count=1, head_ref=63dd3e0f==chaos-version=63dd3e0f,
  version 3.1.0+2.9.4 -> 3.2.0+2.20.6 (HC1 non-vacuous), 5 lifecycle assertions
  + 3 custom-stage assertions all PASS.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/n8n/test_install.py

@@ -20,6 +20,10 @@ def test_serving_and_editor(live_app, meta):
     assert status == 200, f"expected 200 from {live_app}/healthz, got {status}"
 
     # A real browser loads the live n8n editor SPA over HTTPS.
+    # n8n's boot is staged: /healthz returns 200 before / route is registered. So we may briefly
+    # get 404 from /, then a 200 with the "starting up" placeholder, then the actual SPA. Poll
+    # page.goto until status==200 (route registered) — Phase 1e exec_in_app pattern: bounded poll,
+    # no bare sleep, raise on persistent failure.
     from playwright.sync_api import sync_playwright
 
     url = f"https://{live_app}/"
@@ -28,11 +32,20 @@ def test_serving_and_editor(live_app, meta):
         try:
             ctx = browser.new_context(ignore_https_errors=True)
             page = ctx.new_page()
-            resp = page.goto(url, wait_until="domcontentloaded", timeout=60000)
-            assert resp is not None and resp.status in (
-                200,
-                304,
-            ), f"page status {resp and resp.status}"
+            import time
+
+            deadline = time.time() + 120
+            resp = None
+            last_status = 0
+            while time.time() < deadline:
+                resp = page.goto(url, wait_until="domcontentloaded", timeout=30000)
+                last_status = resp.status if resp is not None else 0
+                if last_status in (200, 304):
+                    break
+                time.sleep(3)
+            assert resp is not None and last_status in (200, 304), (
+                f"page status {last_status} after polling — n8n route never came up"
+            )
             body = page.content().lower()
             assert "n8n" in body or "<html" in body, "no n8n content served"
         finally: