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.

packages/devices/src/registry.ts

@@ -35,9 +35,9 @@ export type DeviceConfig = Record<string, string | number | boolean>;
  * fields the admin must supply, and a factory that builds a live adapter.
  */
 export interface DeviceDriver<T extends Device = Device> {
-  readonly id: string; // stable, e.g. "zkteco", "esp32-relay", "hikvision"
+  readonly id: string; // stable, e.g. "dingtian", "hikvision"
   readonly category: DeviceCategory;
-  readonly label: string; // human name for the picker, e.g. "ZKTeco controller"
+  readonly label: string; // human name for the picker, e.g. "Dingtian relay controller"
   readonly description: string;
   /** Transports/notes surfaced in the UI, e.g. ["tcp-ip"], ["wiegand"]. */
   readonly transports: readonly string[];
@@ -53,7 +53,7 @@ export type PrinterDriver = DeviceDriver<PrinterDevice>;
 
 /** A device found on the LAN by a driver's discovery scan. */
 export interface DiscoveredDevice {
-  /** Identifier to pre-fill (e.g. UHPPOTE serial number). */
+  /** Identifier to pre-fill (e.g. a serial number). */
   readonly id: string;
   readonly label: string;
   /** Config values to auto-fill into the setup form (host, serial, …). */
@@ -63,9 +63,10 @@ export interface DiscoveredDevice {
 }
 
 /**
- * Optional capability: a driver that can find devices on the LAN. UHPPOTE
- * implements this via the protocol's UDP broadcast discovery (get-devices);
- * cameras (ONVIF) and others may add it later. See wiki/concepts/device-discovery.md.
+ * Optional capability: a driver that can find devices on the LAN (e.g. UDP
+ * broadcast discovery). No bundled driver implements this yet — the Dingtian
+ * board uses a fixed IP; cameras (ONVIF) or other UDP-discoverable devices may
+ * add it later. See wiki/concepts/device-discovery.md.
  */
 export interface DiscoverableDriver {
   discover(): Promise<DiscoveredDevice[]>;