feat(demo): plain-language integration status, richer audit, reset integrity

Integration status badges across Dashboard/Automation now show honest
plain-language labels instead of raw backend state strings (and fix a
few states that had no matching CSS colour class at all). Audit trail
gets a "view related events" action reusing the existing correlation_id
filter. About page gains scope/architecture/security/testing sections
and a guided-demo entry point. POST /api/v1/demo/reset now runs and
records a server-side scenario-integrity check. Also fixes a second real
race condition (caught by the return-review e2e test): the odometer
scenario pre-fill now resolves before ReturnForm mounts instead of
patching its value in after the fact.

PROJECT_STATE.md

@@ -688,3 +688,51 @@ scenarios, demo manifest, About page). Gap audit: `docs/demo-release/current-dem
 - Exact next action: plain-language integration-status labels, richer audit narration,
   the full "Over deze demo" page content (currently a first pass from Batch 2), and
   wiring reset into the guide/About/OM menu narrative — task #34.
+
+### Batch 5 — integration-status UX, audit UX, About page, reset integrity (complete)
+
+- Plain-language integration status: extracted `frontend/src/data/integrationLabels.ts`
+  (`N8N_STATE_META`/`MCP_STATE_META`) mapping raw backend states to honest labels
+  ("Operational"/"Not connected"/"Prepared"/"Delivery failed"/"Retry available") while
+  keeping each mapped onto an existing `.status-*` CSS colour class (a few raw values like
+  `degraded`/`disabled`/`configured` had no matching CSS rule at all before this — a real,
+  pre-existing colour-coding gap). `StatusBadge` gained an optional `label` override prop
+  (backward compatible) so the badge's colour class and its displayed text can differ.
+  Wired into both `Automation.tsx` and `Dashboard.tsx`'s integration cards; also renamed
+  the "RAGcore" card heading to "Knowledge assistant" and made its text honestly name the
+  actual active provider (same bug class fixed in Knowledge.tsx in Batch 4).
+- Audit trail: added a "Follow-up" column with a "View related events" action per row that
+  filters the same list by `correlation_id` (reuses the backend's existing, already-tested
+  `correlation_id` query param — no new business logic), with a "Clear this filter"
+  affordance. This is how a visitor sees "what else happened as a result of this action"
+  (e.g. a return's linked vehicle-status-changed / workflow-queued events) without a
+  bigger grouped-timeline rebuild.
+- About page: added target-audience/scope, a short architecture summary, security
+  principles, and a testing-approach section (previously only covered the fictional
+  problem/real/synthetic/integrations/reset); added a "Start begeleide demo" CTA for
+  Operations Managers that opens the Demo Guide directly from this page.
+- Reset integrity: added `scenario_integrity_report()` (`backend/app/services/
+  demo_manifest.py`), reusing the exact same scenario-readiness derivation the manifest
+  and scenario overview already use (so it can't drift), and wired it into `POST
+  /api/v1/demo/reset` — both the response body and the `demo_reset` audit event's
+  metadata now carry `scenario_integrity: {all_ready, not_ready}`. This is the
+  server-side post-reset integrity check the brief asks for; visible today via the audit
+  event's raw-detail view, satisfying the requirement without adding a UI banner to a
+  flow that immediately logs the user out and redirects to `/login`.
+- **Fixed a second real regression this batch, caught by the existing return-review
+  e2e test**: restructured the odometer pre-fill so `BookingDetail.tsx` withholds
+  rendering `ReturnForm` until the scenario's canonical odometer has resolved (with a
+  brief "Scenario voorbereiden…" loading state), instead of mounting the form immediately
+  and patching its value in asynchronously. The previous approach raced visibly with
+  Playwright's `fill()` (and would have raced with a real visitor typing quickly),
+  producing a corrupted concatenated value in one observed failure. This also let the
+  now-unnecessary `odometerEditedByUser` ref guard be removed — simpler and more robust
+  than the effect-based patch it replaced.
+- Evidence: `pytest` **127 passed**, `ruff check .` clean, `mypy app` clean (48 files);
+  frontend `tsc -b` clean, `npm run build` clean; full Playwright suite **51 passed**,
+  confirmed stable across three consecutive full runs (given how many timing races this
+  batch and the previous one surfaced, stability was verified deliberately rather than
+  assumed from a single green run).
+- Exact next action: full guided-demo Playwright test + remaining targeted demo tests per
+  section 19 (mobile guide, keyboard nav, all scenario flows, About page, accessibility/
+  reduced-motion/console/network checks) — task #35.