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/server/src/entry-flow.ts

@@ -73,9 +73,9 @@ export class EntryFlow {
 
   async #runEntry(resolved: ResolvedRelay): Promise<void> {
     // CAPACITY GATE (transient only). When the lot is full, refuse transient entry:
-    // no ticket, no vehicle_entry, no open — sign an anomaly. Permit holders are NOT
+    // no ticket, no vehicle_entry, no open — sign an anomaly. Subscribers are NOT
     // gated here (their flow ignores site-full; their own maxConcurrent applies), so
-    // subscribers aren't locked out. "Full" is a soft policy seam for valet over-
+    // they aren't locked out. "Full" is a soft policy seam for valet over-
     // capacity later. See wiki/concepts/capacity-occupancy.md.
     const occ = getOccupancy(this.#db);
     if (occ.full) {