NIX-OS-69.2 — Kitchen Display route + state machine (local)

6/6 local Gate 1 checks passed. All assertions exercised the route handlers in-process via tsx: secret validation (wrong → null, right → shop), full state machine (new → preparing → ready → served) with started_at / ready_at / served_at stamping, served orders drop out of the active list, advance handler returns 404 / 400 / 409 / 200 in the right cases, GET handler filters served orders out. Authed routes (/cafe/pos, /cafe/pos/register/6) still 307 — no regression.

Why no HTTP-layer smoke? The local Next dev server has been running since 2026-04-21. All middleware-bypass routes (/login, /display/*, /kitchen/*) return 500 from webpack HMR staleness on this machine — documented in project_dev_server_bypass_routes_500.md. Authed routes that go through the normal redirect work fine. The route handlers were exercised in-process via tsx instead, and Gate 2 prod will cover the real HTTP contract end-to-end.

00What's new

Public layout app/(public-kitchen)/layout.tsx — minimal full-height shell, no NIX chrome.
Public page app/(public-kitchen)/kitchen/[shopId]/page.tsx — validates the shop secret server-side, server-renders the initial order list (so a cold worker shows current state immediately), passes data to the client.
Kitchen client kitchen-client.tsx — three columns (New / Preparing / Ready), per-order card with line items + customer + note + elapsed-time chip, big touch buttons (Start / Ready / Served), 5s polling, optimistic state transitions with rollback on failure.
API GET /cafe/api/kitchen/[shopId]/orders?t={secret} — active orders only (FIFO).
API POST /cafe/api/kitchen/[shopId]/advance?t={secret} — validates secret + shop scope + linear transition (new→preparing, preparing→ready, ready→served). Cross-shop tampering returns 404 (no ID enumeration leak).
POS TopBar — the ChefHat pill from 69.1 is now a clickable button that window.opens the Kitchen Display URL with the shop's lazy-created secret.
Middleware — /kitchen/* + /api/kitchen/* added to the bypass set (mirrors the Customer Display pattern from R1.7).

NIX-OS-69.2 — Kitchen Display route + state machine LOCAL

00What's new

01DAO round-trip — secret + state machine✓ full lifecycle

02Route handler — advance endpoint guards✓ 404 / 400 / 409 / 200 all hit

03GET handler — active-only filter✓ served drops out

04Stale-dev-server limitation summary

05Test runner — all checks✓ 6/6 passed