tariff composer: admin publishes rate-card versions (pay station now operable)

validateTariffStructure (shared): non-negative ints, ascending block bounds,
only the last block open-ended — a malformed card can't be published.

Routes: GET /api/tariff (active + history, any signed-in role), POST
/api/tariff/versions (publish an immutable, effective-dated version; admin
only). The single site tariff row is created lazily. Editing = publish a new
version; past sessions keep their pricing.

Web: TariffComposer in the admin shell — edit currency, grace windows,
increment, daily cap, lost-ticket fee, and add/remove rate blocks (major-unit
input -> minor on submit); shows active version + history.

Verified via inject: empty -> active null; invalid blocks -> 400 with problem;
valid -> 201; readonly publish -> 403; after publishing, the pay station quote
returns 404 (no session) instead of 409 (no tariff) -- it now prices against the
active card.

apps/server/src/server.ts

@@ -16,6 +16,7 @@ import { authRoutes } from "./routes/auth.js";
 import { deviceRoutes } from "./routes/devices.js";
 import { eventRoutes } from "./routes/events.js";
 import { payRoutes } from "./routes/pay.js";
+import { tariffRoutes } from "./routes/tariffs.js";
 import { printerRoutes } from "./routes/printers.js";
 import { setupRoutes } from "./routes/setup.js";
 
@@ -109,6 +110,10 @@ export async function buildServer(opts: BuildOptions = {}): Promise<FastifyInsta
   const payStation = new PayStation(db, eventLog, app.log);
   await payRoutes(app, payStation);
 
+  // Tariff composer: admin publishes effective-dated, immutable rate-card versions
+  // the pay station prices against. See wiki/concepts/tariff.md.
+  await tariffRoutes(app, db);
+
   const unsubscribeInput = deviceEvents.onInput((e) => {
     // Resolve which lane the device belongs to. -1 marks "device fired but isn't
     // mapped to a lane" (assigned without a lane, or a stale id) — still recorded