A shift becomes a SITE-WIDE accountability period — at most one open at a
time — so every taking is unambiguously attributed to one operator. Login
stays decoupled from shifts (an operator can log in off-shift to review).
Backend:
- ShiftService.currentOpenShift()/requireOpenShift(); open() refuses when ANY
shift is open and throws ShiftAlreadyOpenError{heldBy} (self vs. other).
- requireShift preHandler gates /api/pay, /api/exit, /api/voucher,
/api/barrier/reopen → 409 {code:"no_shift"}; read-only lookups stay open.
- GET /api/shift/current returns site-wide {open:{startedAt,operator},isMine}.
- GET /api/events?since=<iso> for per-shift log scoping (db: re-export gte).
Frontend:
- Header shift button: open / close-mine / disabled-when-another-holds-it.
- Pay/exit modal gate banner (one-click open; "held by X" when another's);
pay/exit/voucher disabled until this operator's shift is open.
- Active-Sessions barrier re-open gated the same way.
- Live feed scoped to the open shift's window; shared useShift() Query
invalidated over the WS on shift_open/shift_z_report/cash_movement.
- sq/en strings for the control + gate.
Wiki: shift.md (site-wide single-open + gate; superseded per-operator note),
booth-console.md (header control + gate), log entry.
Verified: site-wide invariant + heldBy + handover + chain integrity on a
fresh migrated DB (11/11); db/server/web build clean.
Add react-i18next with two key-parity-checked catalogs (sq default/fallback, en).
Active language driven by the logged-in user's stored preference (applied after
/me resolves); SQ/EN toggle in the header persists via PUT /api/auth/language.
Translate the booth (screen, pay/exit modal, active sessions, snapshots, status),
Login, ShiftControl, SiteSettings, PermitManager, TariffComposer.
SetupWizard deferred (its content is server-provided; needs backend catalog i18n).
Add tailwindcss (Bloomberg-terminal theme in index.css), @tanstack/react-query +
react-router, zustand, and Radix primitives. Router with role-guarded routes;
QueryClient wrapping the existing apiFetch; a small Zustand live store fed by a
/api/ws client that invalidates Query caches. Booth screen: live occupancy gauge
+ streaming entry/exit/payment feed. Vite proxies the WS upgrade.
Note: BoothScreen references the pay/exit modal + active-sessions panel added in
following commits; final HEAD builds.