fix(entry): enforce the camera press-gate + duplicate-ticket defenses

Field report (park-buzi): a BLINKING entry button still printed — the lamp
encoded blink-vs-solid (radar-only vs radar+camera) but #suppressReason only
checked the radar, so a radar false-positive (rain, pedestrian) minted a real
signed ticket. Three layered fixes:

1. CAMERA gate on the physical press: with an entry camera configured, a press
   is live only in the lamp's SOLID state (LaneStatus.entry busy, mirrored into
   EntryFlow via onLaneStatus). Suppress-only — the camera stays advisory (never
   opens, never traps). Camera-less sites keep the radar-only gate; a faulty
   camera is dropped via the existing bypassPresenceCamera admin toggle.

2. Cooldown as a REAL backstop behind presence: the presence branch returned
   early, so entryCooldownSec was dead wherever a loop was wired. Now it bounds
   the stationary-car double-ticket (a motion radar drops a motionless car →
   spurious loop-clear re-arms one-car-one-ticket → same car reprints).

3. Post-hoc duplicate-plate anomaly (entry-side twin of plateSwapSuspected):
   when entry ANPR recognizes a plate already OPEN under another session entered
   within ENTRY_DUP_PLATE_WINDOW_MIN (default 15 min), sign ONE
   entry.duplicatePlate anomaly naming both tickets for the operator to void.
   ANPR stays non-blocking (rides the post-open snapshot as before).

REJECTED: camera-vetoed re-arm (defer re-arm until the lane flips free). The
camera has no leave events — "free" is a ~30s silence timeout that never lapses
inside a queue, so every queued car after the first would be suppressed until
an operator intervened. Blocking legit entry at peak beats nothing; the proper
preventive fix is a pass-through sensor (passedInput) — recorded as open in
wiki/concepts/entry-double-press.md.

Also: setup.relayTest reason was missing from both web catalogs (parity is only
enforced sq<->en, so the build passed) — added.

Tests: entry-press-gate.test.ts (blink suppresses / solid prints / camera-less
unaffected / bypass honored / cooldown catches the dropout re-press / residual
risk documented / still-present re-press stays suppressed) +
entry-duplicate-plate.test.ts (flags open dup, ignores closed/stale/self/other
plates). Suite 258 green.

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

apps/server/src/entry-flow.ts

@@ -12,7 +12,7 @@ import {
 } from "@parking/devices";
 import { DEFAULT_VEHICLE_CATEGORY, reasonPayload } from "@parking/shared";
 import type { FastifyBaseLogger } from "fastify";
-import type { DeviceInputEvent } from "./device-events.js";
+import type { DeviceInputEvent, LaneStatusEvent } from "./device-events.js";
 import { getOccupancy } from "./occupancy.js";
 import type { EventLog } from "./event-log.js";
 import { devicesByDirection, firstRelayByDirection, relayForButton, relayForPresence, type ResolvedRelay } from "./device-resolve.js";
@@ -48,6 +48,14 @@ import type { VisionClient } from "./vision-client.js";
 //     input edges to track presence + "armed" per relay.
 //   - COOLDOWN (fallback, no feedback): `entryCooldownSec` suppresses repeat presses on
 //     the relay for N seconds after a ticket. A timer — mitigation, not a guarantee.
+//     When a loop IS wired the cooldown still runs as a BACKSTOP behind it: a motion
+//     radar can drop a STATIONARY car (no doppler return) and spuriously re-arm, and the
+//     cooldown bounds how fast that re-armed press can mint a second ticket.
+//   - CAMERA (when an entry camera is configured): a press is live only while the entry
+//     lane camera confirms a vehicle — the button lamp's SOLID state (button-light.ts).
+//     A radar false-positive (rain, a pedestrian) blinks the lamp but prints nothing.
+//     Camera-less sites keep the radar-only gate; a faulty camera is dropped via the
+//     admin bypass (wiki/concepts/entry-presence-bypass.md).
 // A suppressed press is recorded as UNSIGNED telemetry (a no-op, not a fraud anomaly).
 // See wiki/concepts/entry-double-press.md.
 
@@ -76,6 +84,10 @@ export class EntryFlow {
   readonly #guard = new Map<string, RelayGuardState>();
   /** Optional vision client — passed to snapshotAsync so ANPR runs on the entry image. */
   readonly #vision: VisionClient | null;
+  /** Live entry-lane camera state (LaneStatus mirror, fed by onLaneStatus). Gates the
+   *  physical press when an entry camera is configured — advisory sensor, but here it
+   *  only ever SUPPRESSES a reprint; it never opens a barrier or traps a car. */
+  #entryBusy = false;
 
   constructor(db: Db, log: EventLog, logger: FastifyBaseLogger, vision: VisionClient | null = null) {
     this.#db = db;
@@ -125,6 +137,12 @@ export class EntryFlow {
     }
   }
 
+  /** Track the entry lane's camera state (wired to deviceEvents.onLaneStatus in
+   *  server.ts). LaneStatus emits on every flip, so this mirror stays current. */
+  onLaneStatus(s: LaneStatusEvent): void {
+    this.#entryBusy = s.entry;
+  }
+
   /** Stable per-relay key for the guard map. */
   #relayKey(r: ResolvedRelay): string {
     return `${r.controller.id}:${r.relay}`;
@@ -157,22 +175,35 @@ export class EntryFlow {
   }
 
   /** Why a press should be SUPPRESSED (no ticket), or null if it may proceed.
-   *  PRESENCE mode is authoritative when a loop is wired; otherwise COOLDOWN; else no
-   *  guard (legacy). The two can coexist — presence first, cooldown as a backstop. */
+   *  Three layered gates: CAMERA (when an entry camera is configured), PRESENCE
+   *  (when a loop is wired), and COOLDOWN — no longer alternatives: the cooldown
+   *  runs as a backstop BEHIND presence, because a motion radar can drop a
+   *  stationary car and spuriously re-arm one-car-one-ticket. */
   #suppressReason(r: ResolvedRelay): string | null {
     const s = this.#guardState(r);
+    const bypass = this.#presenceBypass();
+
+    // CAMERA GATE — the lamp's blink-vs-solid rule, enforced at the press: with an entry
+    // camera configured, a press is live only once the camera confirms a vehicle in the
+    // entry zone (SOLID). Blink (radar-only — rain, a pedestrian, a reflection) prints
+    // nothing. Only ever suppresses a ticket; never opens or traps (advisory rule kept).
+    // A camera-less site skips this; a faulty camera is dropped via the admin bypass.
+    if (!bypass.camera && !this.#entryBusy && this.#entryCameraConfigured()) {
+      return "no camera-confirmed vehicle in the entry zone";
+    }
 
     // Admin bypass for a FAULTY radar/loop: skip the presence-loop check so a press prints.
-    // We fall THROUGH to the cooldown backstop below (a dead loop can't re-arm one-car-one-
-    // ticket, so the time cooldown is what stops a held button minting a burst). If no
-    // cooldown is configured there's no anti-double-press left — that's the admin's accepted
-    // tradeoff while bypassed. See wiki/concepts/entry-presence-bypass.md.
-    if (typeof r.presenceInput === "number" && !this.#presenceBypass().radar) {
+    // A dead loop can't re-arm one-car-one-ticket, so the cooldown below is what stops a
+    // held button minting a burst. If no cooldown is configured there's no anti-double-press
+    // left — that's the admin's accepted tradeoff while bypassed. See
+    // wiki/concepts/entry-presence-bypass.md.
+    if (typeof r.presenceInput === "number" && !bypass.radar) {
       // Physical one-car-one-ticket: a car must be present AND we must be armed (no
       // ticket already issued for this still-present car).
       if (!s.present) return "no vehicle at the barrier (presence loop clear)";
       if (!s.armed) return "ticket already issued for the car at the barrier";
-      return null;
+      // Fall THROUGH to the cooldown backstop: a presence-approved press can still be the
+      // SAME stationary car after a radar dropout re-armed the guard.
     }
 
     if (typeof r.entryCooldownSec === "number" && r.entryCooldownSec > 0) {
@@ -185,6 +216,13 @@ export class EntryFlow {
     return null;
   }
 
+  /** Is at least one enabled camera bound to the entry lane? The camera gate applies only
+   *  then — a site with no entry camera keeps the radar-only press gate. Read live (like
+   *  the bypass flags) so adding/removing a camera needs no restart. */
+  #entryCameraConfigured(): boolean {
+    return devicesByDirection(this.#db, "camera", "entry").length > 0;
+  }
+
   /** Record a suppressed (repeat/no-car) entry press as UNSIGNED telemetry — a no-op,
    *  not a fraud anomaly, so the signed ledger stays clean (the operator's choice). */
   #recordSuppressedPress(e: DeviceInputEvent, r: ResolvedRelay, reason: string): void {
@@ -452,7 +490,9 @@ export class EntryFlow {
    *  Used on both the OPEN path and the refused/held anomaly paths — a turned-away or
    *  held car is exactly when the operator wants the photo. */
   #fireSnapshot(direction: "entry", identity: string): void {
-    void snapshotAsync({ db: this.#db, direction, identity, logger: this.#logger, vision: this.#vision }).catch(
+    // `log` lets the ANPR ride-along flag a duplicate-plate entry (a signed anomaly) —
+    // still fire-and-forget; recognition never gates the open. See snapshot.ts.
+    void snapshotAsync({ db: this.#db, direction, identity, logger: this.#logger, vision: this.#vision, log: this.#log }).catch(
       (err) => this.#logger.error(`entry snapshot error: ${(err as Error).message}`),
     );
   }