feat(entry): admin bypass of the presence gate for faulty radar/camera

The entry button (physical press AND the operator-issued mint) requires
radar/loop presence + camera detection to confirm a real vehicle. When one
of those devices is faulty, the gate blocks legitimate transient entry. Let
the ADMIN drop a specific signal as a requirement until support fixes the
hardware — the admin is not the adversary, but weakening an anti-fraud gate
stays attributed and auditable:

- Granular: bypass radar and camera independently (Setup → controller
  section). A dead camera drops only the camera check; a dead radar only
  radar. Both off = normal gate; both on = press-to-print.
- Signed: a DEDICATED endpoint (PUT /api/site-config/presence-bypass,
  site:update) appends a signed config_change {setting, value, prev,
  operator} per actually-changed signal — new ledger type. No-op toggles
  sign nothing; disabling signs too. Kept out of the generic site PUT.
- Flagged: every vehicle_entry issued (and every refusal anomaly) while
  bypassed carries presenceBypassed:[...] in its signed payload.
- Persists until turned off; amber warning in Setup while active. The
  booth entry light treats a bypassed signal as satisfied (server
  re-checks authoritatively). Physical-button path falls through to the
  cooldown backstop when radar is bypassed.
- Migration 0020: two boolean site_config columns (default off).

Fixes a latent bug surfaced by the tests: firstRelayByDirection returned no
presenceInput, so issueForOperator's radar gate always read "presence loop
unavailable" — operator-issue never actually gated on radar. The resolver
now attaches the presence input serving the relay (mirrors relayForButton).

10 new tests: 5 gate combinations (each bypass drops only its signal +
records it), 5 route tests (RBAC, signed transitions, no-op, validation).

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

apps/server/src/device-resolve.ts

@@ -289,7 +289,19 @@ export function firstRelayByDirection(db: Db, direction: FlowDirection): Resolve
       (r): r is RelaySpec & { direction: Direction } =>
         r.direction === direction || r.direction === "both",
     );
-    if (spec) return { controller, relay: spec.relay, direction: spec.direction };
+    if (spec) {
+      // Attach the presence sensor (if any) serving the SAME relay, so callers that gate on
+      // presence (the operator-issued entry) see it. Without this the ResolvedRelay carried
+      // no presenceInput and the presence gate read as "unavailable". Mirrors relayForButton.
+      const presence = inputsOf(controller).find((i) => i.role === "presence" && i.relay === spec.relay);
+      return {
+        controller,
+        relay: spec.relay,
+        direction: spec.direction,
+        presenceInput: presence?.input,
+        presenceKind: presence?.kind ?? "loop",
+      };
+    }
   }
   return null;
 }