feat(subscription): rename permit→subscription + monthly pricing

The "permit/lejet" feature is really a subscription. Full rename of the
mutable master data, plus a recurring monthly price.

- DB (migration 0004, data-preserving ALTER RENAME): permits→subscriptions,
  permit_credentials/_plates→subscription_*, sessions.permit_id→subscription_id.
- Pricing: per-subscription priceMinor + period(monthly) + currency, with a
  site default (site_config.subscription_monthly_price_minor) pre-filling the form.
- Server: subscription-flow.ts (SubscriptionFlow), routes/subscriptions.ts
  (/api/subscriptions). Web: SubscriptionManager, route, i18n (sq Abonimet/en).
- The signed ledger `permitId` payload is intentionally kept — immutable
  hash-chained history; renaming it would break verification of past events.

Deferred (wiki notes): fee collection into the ledger/shift (a shift-attributed
payment), LPR/ANPR plate source, time-of-day access windows (overnight subscriber).

Also carries the device-footer UI surface (api DeviceStatus, router mount,
i18n devices) due to shared-file overlap with the preceding footer commit.

Verified end-to-end on a fresh DB and migration on a live-DB copy (sessions
preserved). Live DB migrated. Full monorepo builds clean.

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V

apps/web/src/router.tsx

@@ -15,11 +15,12 @@ import { qk, queryClient } from "./lib/query.js";
 import { setLanguage } from "./lib/i18n/index.js";
 import { useLiveFeed } from "./lib/use-live-feed.js";
 import { useShift } from "./lib/use-shift.js";
+import { DeviceFooter } from "./ui/DeviceFooter.js";
 import { StatusDot } from "./ui/StatusDot.js";
 import { BoothScreen } from "./BoothScreen.js";
 import { SetupWizard } from "./SetupWizard.js";
 import { TariffComposer } from "./TariffComposer.js";
-import { PermitManager } from "./PermitManager.js";
+import { SubscriptionManager } from "./SubscriptionManager.js";
 import { ShiftControl } from "./ShiftControl.js";
 import { SiteSettings } from "./SiteSettings.js";
 
@@ -164,7 +165,7 @@ function RootLayout() {
           <NavLink to="/shift" label={t("nav.shift")} />
           {isAdmin && <NavLink to="/setup" label={t("nav.setup")} />}
           {isAdmin && <NavLink to="/tariff" label={t("nav.tariff")} />}
-          {isAdmin && <NavLink to="/permits" label={t("nav.permits")} />}
+          {isAdmin && <NavLink to="/subscriptions" label={t("nav.subscriptions")} />}
           {isAdmin && <NavLink to="/site" label={t("nav.site")} />}
         </nav>
         <div className="ml-auto flex items-center gap-3">
@@ -189,6 +190,8 @@ function RootLayout() {
       <main className="min-h-0 flex-1 overflow-auto p-3">
         <Outlet />
       </main>
+      {/* Fixed device-status footer — relays, readers, cameras, printers. */}
+      {user && <DeviceFooter />}
     </div>
   );
 }
@@ -233,11 +236,11 @@ const tariffRoute = createRoute({
   beforeLoad: ({ context }) => adminOnly(context),
   component: () => <TariffComposer />,
 });
-const permitsRoute = createRoute({
+const subscriptionsRoute = createRoute({
   getParentRoute: () => rootRoute,
-  path: "/permits",
+  path: "/subscriptions",
   beforeLoad: ({ context }) => adminOnly(context),
-  component: () => <PermitManager />,
+  component: () => <SubscriptionManager />,
 });
 const siteRoute = createRoute({
   getParentRoute: () => rootRoute,
@@ -252,7 +255,7 @@ const routeTree = rootRoute.addChildren([
   shiftRoute,
   setupRoute,
   tariffRoute,
-  permitsRoute,
+  subscriptionsRoute,
   siteRoute,
 ]);