feat: updated integration page with missing API routes

features/integration.qa.md

@@ -54,7 +54,7 @@ Component specs, one per design state:
 6. **Session only**: the corrected banner; lock icon and "Session only" chip only on rows that
    answer 403; the caption on the login family; no expand control; the "Public auth flow" rows with
    the "Public" chip.
-7. **Errors**: table rows 400, 401, 403, 404, 409, 429, 500 with the real strings and the 403
+7. **Errors**: table rows 400, 401, 403, 404, 409, 422, 429, 500 with the real strings and the 403
    sample block.
 8. **Navigation**: clicking an index item sets aria-current and scrolls to its anchor; the mobile
    "Jump to" lists the same sections.