Remove UHPPOTE/ZKTeco; Dingtian is the only access driver

Neither UHPPOTE nor ZKTeco is used — the Dingtian relay controller was chosen
and verified. Remove their code and re-scope the wiki.

Code:
- delete access-uhppote.ts, uhppoted.d.ts, access.ts (zkteco/esp32-relay stubs),
  and the three uhppote-*.mjs hardware test scripts.
- remove the `uhppoted` npm dependency from @parking/devices and @parking/server.
- unregister uhppote/zkteco/esp32-relay from the driver registry; drop their
  exports. Catalog access drivers = dingtian only. Build green (5/5).
- refresh now-stale example comments (registry/interfaces/setup/api) to use
  current examples; keep the two "UHPPOTE blocker" references that explain why
  the precondition capability exists.

Wiki (kept pages, re-scoped):
- uhppote-controller, zkteco-controller -> rejected/historical with callouts;
  uhppote-vs-esp32 -> historical (detection-vs-prevention lens still useful).
- re-point all "current device" framing (standing-decisions, bom, overview,
  open-questions, device-registry, device-discovery, index) to dingtian-relay.
- transferable concepts (network-isolation, event-log-ingestion, barrier-not-a-
  door, threat-model) untouched. Raw source immutable. Links lint clean.

apps/server/src/routes/setup.ts

@@ -28,14 +28,14 @@ export async function setupRoutes(app: FastifyInstance, db: Db): Promise<void> {
   const adminGuard = requireRole("admin");
 
   // Catalog of selectable drivers per category (no secrets — schema only).
-  // `discoverable` flags drivers that can scan the LAN (e.g. UHPPOTE).
+  // `discoverable` flags drivers that can scan the LAN.
   app.get("/api/setup/catalog", async () => {
     const catalog = registry.catalog();
     const discoverable = registry.list().filter(isDiscoverable).map((d) => d.id);
     return { ...catalog, discoverable };
   });
 
-  // Scan the LAN for devices a driver can discover (UHPPOTE UDP broadcast, etc).
+  // Scan the LAN for devices a driver can discover (UDP broadcast, etc).
   // Each found device is health-checked so the admin sees reachability before
   // assigning. Admin-only. See wiki/concepts/device-discovery.md.
   app.get<{ Params: { driverId: string } }>(