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;
 }

apps/server/src/entry-flow.ts

@@ -51,6 +51,10 @@ import type { VisionClient } from "./vision-client.js";
 // A suppressed press is recorded as UNSIGNED telemetry (a no-op, not a fraud anomaly).
 // See wiki/concepts/entry-double-press.md.
 
+/** A presence signal the entry gate can require (or, when a device is faulty, the admin
+ *  can bypass): the radar/loop presence input, or the camera vehicle-detection. */
+export type PresenceSignal = "radar" | "camera";
+
 /** Per-relay anti-double-press state, keyed `controllerId:relay`. */
 interface RelayGuardState {
   /** Last successful ticket time (ms epoch) — drives the cooldown check. */
@@ -158,7 +162,12 @@ export class EntryFlow {
   #suppressReason(r: ResolvedRelay): string | null {
     const s = this.#guardState(r);
 
-    if (typeof r.presenceInput === "number") {
+    // 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) {
       // 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)";
@@ -244,7 +253,14 @@ export class EntryFlow {
    */
   async #issueTicket(
     resolved: ResolvedRelay,
-    opts: { source: "ticket" | "manual"; operator?: string; overCapacity?: { count: number; capacity: number | null } },
+    opts: {
+      source: "ticket" | "manual";
+      operator?: string;
+      overCapacity?: { count: number; capacity: number | null };
+      /** Presence signals that were BYPASSED (admin dropped them due to faulty hardware).
+       *  Recorded on the signed entry so a ticket issued under a weakened gate is auditable. */
+      presenceBypassed?: PresenceSignal[];
+    },
   ): Promise<{ ok: true; ticketId: string; opened: boolean } | { ok: false; reason: string }> {
     const ticketId = newTicketId();
     const issuedAt = new Date().toISOString();
@@ -304,6 +320,9 @@ export class EntryFlow {
         category,
         ...(operatorInitiated ? { operatorInitiated: true, operator: opts.operator } : {}),
         ...(opts.overCapacity ? { lotFull: true, occupancy: `${opts.overCapacity.count}/${opts.overCapacity.capacity ?? "∞"}` } : {}),
+        ...(opts.presenceBypassed && opts.presenceBypassed.length > 0
+          ? { presenceBypassed: opts.presenceBypassed }
+          : {}),
       },
       occurredAt: issuedAt,
     });
@@ -366,13 +385,33 @@ export class EntryFlow {
     const resolved = firstRelayByDirection(this.#db, "entry");
     if (!resolved) return { ok: false, reason: "no entry barrier configured" };
 
-    // PRESENCE GATE — require BOTH a presence loop (configured + currently occupied) AND
-    // the camera confirming a vehicle. No loop configured → feature unavailable here.
-    if (typeof resolved.presenceInput !== "number") {
-      return { ok: false, reason: "no presence loop on the entry barrier — operator issue unavailable" };
+    // PRESENCE GATE — normally require BOTH radar/loop presence AND camera detection. An
+    // admin may BYPASS a signal when its device is faulty (site_config, signed config_change);
+    // the bypassed signal is dropped as a requirement and RECORDED on the issued ticket.
+    const bypass = this.#presenceBypass();
+    const bypassed: PresenceSignal[] = [];
+
+    // Radar/loop side. A configured loop is only mandatory while radar is still REQUIRED;
+    // if radar is bypassed we skip the loop entirely (a dead loop is exactly why they bypass).
+    const radarRequired = !bypass.radar;
+    let radarPresent: boolean | null = null;
+    if (radarRequired) {
+      if (typeof resolved.presenceInput !== "number") {
+        return { ok: false, reason: "no presence loop on the entry barrier — operator issue unavailable (or bypass radar)" };
+      }
+      radarPresent = this.#guardState(resolved).present;
+    } else {
+      bypassed.push("radar");
     }
-    const present = this.#guardState(resolved).present;
-    if (!present || !cameraBusy) {
+
+    // Camera side.
+    const cameraRequired = !bypass.camera;
+    if (!cameraRequired) bypassed.push("camera");
+
+    // Refuse only when a STILL-REQUIRED signal fails to confirm a vehicle.
+    const radarOk = !radarRequired || radarPresent === true;
+    const cameraOk = !cameraRequired || cameraBusy;
+    if (!radarOk || !cameraOk) {
       await this.#log.append({
         type: "anomaly",
         identity: `ENTRY-ATTEMPT-${randomUUID().replace(/-/g, "").slice(0, 12)}`,
@@ -380,11 +419,14 @@ export class EntryFlow {
           ...reasonPayload("entry.issue.noPresence", { operator }),
           source: "booth",
           operator,
-          radarPresent: present,
+          radarPresent,
           cameraBusy,
+          ...(bypassed.length > 0 ? { presenceBypassed: bypassed } : {}),
         },
       });
-      this.#logger.warn(`operator entry refused by ${operator}: no vehicle present (radar=${present}, camera=${cameraBusy})`);
+      this.#logger.warn(
+        `operator entry refused by ${operator}: no vehicle present (radar=${radarPresent}, camera=${cameraBusy}, bypassed=[${bypassed.join(",")}])`,
+      );
       return { ok: false, reason: "no vehicle detected at the entry" };
     }
 
@@ -397,6 +439,7 @@ export class EntryFlow {
         source: "manual",
         operator,
         ...(occ.full ? { overCapacity: { count: occ.count, capacity: occ.capacity ?? null } } : {}),
+        ...(bypassed.length > 0 ? { presenceBypassed: bypassed } : {}),
       });
       if (!res.ok) return res;
       return { ok: true, ticketId: res.ticketId, opened: res.opened, overCapacity: occ.full };
@@ -414,6 +457,13 @@ export class EntryFlow {
     );
   }
 
+  /** Current admin presence-gate bypass (site_config), read LIVE so a toggle takes effect
+   *  with no restart. Default: nothing bypassed (the normal both-required gate). */
+  #presenceBypass(): { radar: boolean; camera: boolean } {
+    const cfg = this.#db.select().from(siteConfig).where(eq(siteConfig.id, 1)).get();
+    return { radar: cfg?.bypassPresenceRadar ?? false, camera: cfg?.bypassPresenceCamera ?? false };
+  }
+
   /** Build a live access adapter from a resolved controller row, or null. */
   #buildAccess(row: DeviceRow): AccessControlDevice | null {
     const driver = registry.get(row.driverId);

apps/server/src/entry-presence-bypass.test.ts

@@ -0,0 +1,112 @@
+import { beforeEach, describe, expect, it } from "vitest";
+import { devices, siteConfig, ledgerEvents, type Db } from "@parking/db";
+import { createTestDb } from "@parking/db/testing";
+import { EntryFlow } from "./entry-flow.js";
+import { makeLog, silentLogger } from "./test-helpers.js";
+
+// The entry presence gate normally requires BOTH radar/loop presence AND camera detection.
+// An admin may BYPASS a signal when its device is faulty (site_config, set via a signed
+// endpoint). These tests pin the GATE decision in EntryFlow.issueForOperator under each
+// bypass combination: a still-required-but-absent signal refuses (+ signs an anomaly); a
+// bypassed signal is dropped and recorded. We assert the gate outcome via the refuse path
+// (deterministic, no printer needed); the allow path is proven by getting PAST the gate
+// (it then fails at printing — a different reason — which is exactly "the gate opened").
+
+let db: Db;
+let flow: EntryFlow;
+
+const CTL = "ctl-entry";
+const PRESENCE_INPUT = 2;
+
+beforeEach(() => {
+  ({ db } = createTestDb());
+  // A controller with an entry barrier (R1), a presence loop on input 2, and an entry button
+  // on input 1 — the shape device-resolve expects (relays[] + inputs[]).
+  db.insert(devices).values({
+    id: CTL,
+    category: "access",
+    driverId: "stub-access",
+    config: {
+      relays: [{ relay: 1, direction: "entry" }],
+      inputs: [
+        { input: 1, role: "button", relay: 1 },
+        { input: PRESENCE_INPUT, role: "presence", relay: 1, kind: "loop" },
+      ],
+    },
+    enabled: true,
+  }).run();
+  flow = new EntryFlow(db, makeLog(db), silentLogger());
+});
+
+function setBypass(patch: { radar?: boolean; camera?: boolean }) {
+  db.insert(siteConfig)
+    .values({ id: 1, bypassPresenceRadar: patch.radar ?? false, bypassPresenceCamera: patch.camera ?? false })
+    .onConflictDoUpdate({
+      target: siteConfig.id,
+      set: { bypassPresenceRadar: patch.radar ?? false, bypassPresenceCamera: patch.camera ?? false },
+    })
+    .run();
+}
+
+/** Drive a presence loop edge so the flow's per-relay guard marks a car present/clear. */
+async function setRadarPresent(present: boolean) {
+  await flow.onInput({
+    driverId: "stub-access",
+    deviceId: CTL,
+    input: PRESENCE_INPUT,
+    edge: present ? "on" : "off",
+    at: new Date().toISOString(),
+    source: "poll",
+  });
+}
+
+const anomalies = () =>
+  db.select().from(ledgerEvents).all().filter((r) => r.type === "anomaly");
+
+describe("entry presence-gate bypass", () => {
+  it("no bypass + no vehicle → refuses and signs a noPresence anomaly", async () => {
+    const res = await flow.issueForOperator("admin", /*cameraBusy*/ false);
+    expect(res.ok).toBe(false);
+    expect(anomalies()).toHaveLength(1);
+    expect(anomalies()[0].payload).toMatchObject({ reasonCode: "entry.issue.noPresence" });
+  });
+
+  it("camera bypassed + radar present → gate OPENS (no refuse anomaly)", async () => {
+    setBypass({ camera: true });
+    await setRadarPresent(true);
+    const res = await flow.issueForOperator("admin", /*cameraBusy*/ false); // camera absent but bypassed
+    // Gate passed: no noPresence refusal. (It then proceeds to print — no printer configured,
+    // so it HOLDS with a print reason, not a presence reason. Either way the gate opened.)
+    const refusals = anomalies().filter((a) => (a.payload as { reasonCode?: string }).reasonCode === "entry.issue.noPresence");
+    expect(refusals).toHaveLength(0);
+    if (!res.ok) expect(res.reason).not.toMatch(/no vehicle detected/);
+  });
+
+  it("radar bypassed + camera busy → gate OPENS even with NO presence loop reading", async () => {
+    setBypass({ radar: true });
+    // radar NOT set present; camera busy=true → radar dropped, camera satisfies.
+    const res = await flow.issueForOperator("admin", /*cameraBusy*/ true);
+    const refusals = anomalies().filter((a) => (a.payload as { reasonCode?: string }).reasonCode === "entry.issue.noPresence");
+    expect(refusals).toHaveLength(0);
+    if (!res.ok) expect(res.reason).not.toMatch(/no vehicle detected/);
+  });
+
+  it("camera bypassed but radar STILL required and absent → refuses (only the faulty signal is dropped)", async () => {
+    setBypass({ camera: true });
+    await setRadarPresent(false); // radar required (not bypassed) and clear
+    const res = await flow.issueForOperator("admin", /*cameraBusy*/ true);
+    expect(res.ok).toBe(false);
+    const refusal = anomalies().find((a) => (a.payload as { reasonCode?: string }).reasonCode === "entry.issue.noPresence");
+    expect(refusal, "the still-required radar gates the button").toBeTruthy();
+    // The refusal records which signal was bypassed (audit).
+    expect(refusal!.payload).toMatchObject({ presenceBypassed: ["camera"] });
+  });
+
+  it("both bypassed → gate OPENS with no radar and no camera (press-to-print)", async () => {
+    setBypass({ radar: true, camera: true });
+    const res = await flow.issueForOperator("admin", /*cameraBusy*/ false);
+    const refusals = anomalies().filter((a) => (a.payload as { reasonCode?: string }).reasonCode === "entry.issue.noPresence");
+    expect(refusals).toHaveLength(0);
+    if (!res.ok) expect(res.reason).not.toMatch(/no vehicle detected/);
+  });
+});

apps/server/src/routes/presence-bypass-route.test.ts

@@ -0,0 +1,91 @@
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { ledgerEvents, type Db } from "@parking/db";
+import { createTestDb } from "@parking/db/testing";
+import type { FastifyInstance } from "fastify";
+import { buildServer } from "../server.js";
+import { seedUser, login } from "../test-helpers.js";
+
+// PUT /api/site-config/presence-bypass toggles the entry presence-gate bypass. It's a
+// DEDICATED, SIGNED endpoint: each signal that actually changes appends a config_change to
+// the ledger (attributed), and it persists to site_config. Admin-only.
+
+let db: Db;
+let close: () => void;
+let app: FastifyInstance;
+
+beforeEach(async () => {
+  const t = createTestDb();
+  db = t.db;
+  close = t.close;
+  app = await buildServer({ db });
+  await app.ready();
+});
+afterEach(async () => {
+  await app.close();
+  close();
+});
+
+const configChanges = () => db.select().from(ledgerEvents).all().filter((r) => r.type === "config_change");
+
+async function put(body: unknown, auth: { cookie: string; csrf: string }) {
+  return app.inject({
+    method: "PUT",
+    url: "/api/site-config/presence-bypass",
+    headers: { cookie: auth.cookie, "x-csrf-token": auth.csrf },
+    payload: body as Record<string, unknown>,
+  });
+}
+
+describe("PUT /api/site-config/presence-bypass", () => {
+  it("is admin-only: a non-site:update user is 403", async () => {
+    await seedUser(db, { username: "op", password: "pw", roleId: "operator", permissions: ["shift:read"] });
+    const auth = await login(app, "op", "pw");
+    const res = await put({ camera: true }, auth);
+    expect(res.statusCode).toBe(403);
+  });
+
+  it("enabling a signal persists it AND signs an attributed config_change", async () => {
+    await seedUser(db, { username: "admin", password: "pw" });
+    const auth = await login(app, "admin", "pw");
+
+    const res = await put({ camera: true }, auth);
+    expect(res.statusCode).toBe(200);
+    expect(res.json()).toMatchObject({ bypassPresenceCamera: true, bypassPresenceRadar: false });
+
+    const changes = configChanges();
+    expect(changes).toHaveLength(1);
+    expect(changes[0].source).toBe("manual");
+    expect(changes[0].signature.length).toBeGreaterThan(0);
+    expect(changes[0].payload).toMatchObject({
+      setting: "entryPresenceBypass.camera",
+      value: true,
+      prev: false,
+      operator: "admin",
+    });
+  });
+
+  it("a no-op toggle (already in that state) signs nothing", async () => {
+    await seedUser(db, { username: "admin", password: "pw" });
+    const auth = await login(app, "admin", "pw");
+    await put({ camera: true }, auth); // 1st: on → 1 event
+    await put({ camera: true }, auth); // 2nd: still on → no new event
+    expect(configChanges()).toHaveLength(1);
+  });
+
+  it("disabling signs the off transition too (auditable both ways)", async () => {
+    await seedUser(db, { username: "admin", password: "pw" });
+    const auth = await login(app, "admin", "pw");
+    await put({ radar: true }, auth);
+    await put({ radar: false }, auth);
+    const changes = configChanges();
+    expect(changes).toHaveLength(2);
+    expect(changes[1].payload).toMatchObject({ setting: "entryPresenceBypass.radar", value: false, prev: true });
+  });
+
+  it("rejects a non-boolean and an empty body", async () => {
+    await seedUser(db, { username: "admin", password: "pw" });
+    const auth = await login(app, "admin", "pw");
+    expect((await put({ camera: "yes" }, auth)).statusCode).toBe(400);
+    expect((await put({}, auth)).statusCode).toBe(400);
+  });
+});

apps/server/src/routes/site.ts

@@ -1,6 +1,7 @@
 import type { FastifyInstance } from "fastify";
 import { eq, siteConfig, type Db } from "@parking/db";
 import { requirePermission } from "../auth.js";
+import type { EventLog } from "../event-log.js";
 import { getOccupancy } from "../occupancy.js";
 
 // Site config (capacity) + live occupancy. Occupancy is a fold over the signed
@@ -38,13 +39,15 @@ interface SiteConfigBody extends Partial<Record<TextField, string | null>> {
 }
 
 /** Shape returned by GET/PUT: capacity + the booth flag + the subscription default
- *  + every metadata field. */
+ *  + the entry presence-bypass flags + every metadata field. */
 type SiteConfig = {
   capacity: number | null;
   exitVoucherDefault: boolean;
   subscriptionMonthlyPriceMinor: number | null;
   reserveSubscriberSpots: boolean;
   anprEntryEnabled: boolean;
+  bypassPresenceRadar: boolean;
+  bypassPresenceCamera: boolean;
 } & Record<TextField, string | null>;
 
 function toSiteConfig(row: typeof siteConfig.$inferSelect | undefined): SiteConfig {
@@ -54,6 +57,8 @@ function toSiteConfig(row: typeof siteConfig.$inferSelect | undefined): SiteConf
     subscriptionMonthlyPriceMinor: row?.subscriptionMonthlyPriceMinor ?? null,
     reserveSubscriberSpots: row?.reserveSubscriberSpots ?? false,
     anprEntryEnabled: row?.anprEntryEnabled ?? true,
+    bypassPresenceRadar: row?.bypassPresenceRadar ?? false,
+    bypassPresenceCamera: row?.bypassPresenceCamera ?? false,
   } as SiteConfig;
   for (const f of TEXT_FIELDS) out[f] = row?.[f] ?? null;
   return out;
@@ -66,7 +71,7 @@ function normText(v: unknown): string | null {
   return s === "" ? null : s;
 }
 
-export async function siteRoutes(app: FastifyInstance, db: Db): Promise<void> {
+export async function siteRoutes(app: FastifyInstance, db: Db, eventLog?: EventLog | null): Promise<void> {
   const readGuard = requirePermission("site:read");
   const writeGuard = requirePermission("site:update");
 
@@ -131,4 +136,64 @@ export async function siteRoutes(app: FastifyInstance, db: Db): Promise<void> {
     const row = db.select().from(siteConfig).where(eq(siteConfig.id, 1)).get();
     return toSiteConfig(row);
   });
+
+  // Entry presence-gate BYPASS — a DEDICATED, SIGNED endpoint (not the generic PUT above),
+  // because dropping a radar/camera requirement weakens an anti-fraud gate. The admin is not
+  // the adversary (a faulty device blocks legit entry until support fixes it), but the change
+  // must be attributed + auditable: each toggled signal appends a signed `config_change`
+  // {setting, value, prev, operator}. Granular per signal. See wiki/concepts/entry-presence-bypass.md.
+  app.put<{ Body: { radar?: boolean; camera?: boolean } }>(
+    "/api/site-config/presence-bypass",
+    { preHandler: writeGuard },
+    async (req, reply) => {
+      const body = req.body ?? {};
+      for (const k of ["radar", "camera"] as const) {
+        if (k in body && typeof body[k] !== "boolean") {
+          return reply.code(400).send({ error: `${k} must be a boolean` });
+        }
+      }
+      if (!("radar" in body) && !("camera" in body)) {
+        return reply.code(400).send({ error: "nothing to change (send radar and/or camera)" });
+      }
+
+      const existing = db.select().from(siteConfig).where(eq(siteConfig.id, 1)).get();
+      const prev = {
+        radar: existing?.bypassPresenceRadar ?? false,
+        camera: existing?.bypassPresenceCamera ?? false,
+      };
+      const next = {
+        radar: "radar" in body ? (body.radar as boolean) : prev.radar,
+        camera: "camera" in body ? (body.camera as boolean) : prev.camera,
+      };
+
+      // Sign a config_change for each signal that ACTUALLY changed (before persisting, so the
+      // audit record exists whether or not a later write hiccups). No-op toggles sign nothing.
+      const operator = req.user?.username ?? "unknown";
+      for (const signal of ["radar", "camera"] as const) {
+        if (next[signal] !== prev[signal]) {
+          await eventLog?.append({
+            type: "config_change",
+            source: "manual",
+            identity: `presence-bypass:${signal}`,
+            payload: {
+              setting: `entryPresenceBypass.${signal}`,
+              value: next[signal],
+              prev: prev[signal],
+              operator,
+            },
+          });
+        }
+      }
+
+      const updatedAt = new Date().toISOString();
+      const patch = { bypassPresenceRadar: next.radar, bypassPresenceCamera: next.camera, updatedAt };
+      if (existing) {
+        db.update(siteConfig).set(patch).where(eq(siteConfig.id, 1)).run();
+      } else {
+        db.insert(siteConfig).values({ id: 1, ...patch }).run();
+      }
+      const row = db.select().from(siteConfig).where(eq(siteConfig.id, 1)).get();
+      return toSiteConfig(row);
+    },
+  );
 }

apps/server/src/server.ts

@@ -279,7 +279,7 @@ export async function buildServer(opts: BuildOptions = {}): Promise<FastifyInsta
 
   // Site config (capacity) + live occupancy. The FULL gate (refuse transient entry
   // at capacity) is in the entry flow. See wiki/concepts/capacity-occupancy.md.
-  await siteRoutes(app, db);
+  await siteRoutes(app, db, eventLog);
 
   // Application logs: ingest frontend errors (POST /api/logs, any signed-in user) +
   // read the store (GET /api/logs, log:read). See wiki/concepts/app-logs.md.