feat(devices): radar presence input + button-light output on the controller

Model the entry button (I1) and a Hikvision radar (I2) as named children of the
access controller, and drive the button's 12V lamp on a spare relay.

- Radar = the existing relays[].presenceInput one-car-one-ticket gate, now labelled
  presenceKind: loop|radar. A radar may idle opposite the button, so add a per-input
  active-level override: relays[].presenceActiveLow -> driver inputActiveLow set,
  inverting just that terminal (pure helper inputActive()). The Dingtian has one
  board-wide resting level otherwise.
- AuxOutputDevice.setAux(channel,on) capability on the device interface (Dingtian
  latch) so business logic drives a NON-barrier lamp through the interface. Barriers
  still only pulseOpen — barrier-not-a-door preserved.
- ButtonLightController: subscribes to the radar input edge + the camera lane status
  and drives a 3-state lamp — radar+car=solid, radar-only=blink (~1Hz), else off.
  Fails OFF on host loss/error; de-duped. A radar detection never opens a barrier on
  its own (advisory; threat model).
- SetupWizard: presence kind + active-low + a button-light relay picker; sq+en i18n.

Tests: button-light.test.ts (truth table + blink + fail-OFF + de-dupe),
access-dingtian.test.ts (active-level inversion). Workspace build+lint+test green
(158 server tests). Wiki: hikvision-radar, button-light-indicator + updates.

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

apps/web/src/api.ts

@@ -286,9 +286,24 @@ export interface RelaySpec {
    *  loop/barrier-feedback signal; a press prints only with a car present + re-arms when
    *  it clears. COOLDOWN (fallback, no feedback): suppress repeat presses for N seconds. */
   presenceInput?: number;
+  /** Sensor on the presence input: induction LOOP or a RADAR (label only). */
+  presenceKind?: "loop" | "radar";
+  /** The presence terminal is active-LOW (idles HIGH) — e.g. a radar wired opposite
+   *  the button. Maps to the driver's per-input active-level override. */
+  presenceActiveLow?: boolean;
   entryCooldownSec?: number;
 }
 
+/** A non-barrier indicator lamp wired to a spare relay (e.g. the entry button light),
+ *  driven by the radar input vs. the camera lane status. */
+export interface ButtonLightSpec {
+  /** 1-based spare relay the lamp is on. */
+  relay: number;
+  /** Blink cadence (ms on / ms off) for the radar-only state. Default 500/500. */
+  blinkOnMs?: number;
+  blinkOffMs?: number;
+}
+
 export interface TestResult {
   health: { status: string; detail?: string };
   preconditions: {