fix(gateway): bound talk handoff expiry

src/gateway/talk-handoff.test.ts

@@ -107,6 +107,45 @@ describe("talk handoff store", () => {
     vi.useRealTimers();
   });
 
+  it("expires handoffs immediately when the creation clock is invalid", () => {
+    clearTalkHandoffsForTest();
+    const dateNow = vi.spyOn(Date, "now").mockReturnValue(Number.NaN);
+    try {
+      const handoff = createTalkHandoff({
+        sessionKey: "session:main",
+        ttlMs: 5000,
+      });
+
+      expect(handoff.createdAt).toBe(0);
+      expect(handoff.expiresAt).toBe(0);
+      expect(joinTalkHandoff(handoff.id, handoff.token)).toEqual({
+        ok: false,
+        reason: "expired",
+      });
+    } finally {
+      dateNow.mockRestore();
+    }
+  });
+
+  it("expires handoffs immediately when expiry would exceed Date bounds", () => {
+    clearTalkHandoffsForTest();
+    vi.useFakeTimers();
+    vi.setSystemTime(new Date(8_640_000_000_000_000));
+
+    const handoff = createTalkHandoff({
+      sessionKey: "session:main",
+      ttlMs: 5000,
+    });
+
+    expect(handoff.expiresAt).toBe(0);
+    expect(joinTalkHandoff(handoff.id, handoff.token)).toEqual({
+      ok: false,
+      reason: "expired",
+    });
+
+    vi.useRealTimers();
+  });
+
   it("joins and revokes handoffs with only the bearer token", () => {
     clearTalkHandoffsForTest();
     const handoff = createTalkHandoff({ sessionKey: "session:main" });

src/gateway/talk-handoff.ts

@@ -1,4 +1,10 @@
 import { createHash, randomBytes, randomUUID } from "node:crypto";
+import {
+  asDateTimestampMs,
+  isFutureDateTimestampMs,
+  resolveDateTimestampMs,
+  resolveExpiresAtMsFromDurationMs,
+} from "../shared/number-coercion.js";
 import { normalizeOptionalString } from "../shared/string-coerce.js";
 import { recordTalkObservabilityEvent } from "../talk/observability.js";
 import {
@@ -99,8 +105,10 @@ const handoffs = new Map<string, TalkHandoffRecord>();
 
 export function createTalkHandoff(params: TalkHandoffCreateParams): TalkHandoffCreateResult {
   pruneExpiredTalkHandoffs();
-  const createdAt = Date.now();
+  const rawCreatedAt = Date.now();
+  const createdAt = resolveDateTimestampMs(rawCreatedAt);
   const ttlMs = normalizeTtlMs(params.ttlMs);
+  const expiresAt = resolveExpiresAtMsFromDurationMs(ttlMs, { nowMs: rawCreatedAt }) ?? 0;
   const id = randomUUID();
   const roomId = `talk_${id}`;
   const token = randomBytes(32).toString("base64url");
@@ -127,7 +135,7 @@ export function createTalkHandoff(params: TalkHandoffCreateParams): TalkHandoffC
     transport: params.transport ?? "managed-room",
     brain: params.brain ?? "agent-consult",
     createdAt,
-    expiresAt: createdAt + ttlMs,
+    expiresAt,
     room,
   };
   appendTalkHandoffRoomEvent(record, {
@@ -285,8 +293,12 @@ function normalizeTtlMs(value: number | undefined): number {
 }
 
 function pruneExpiredTalkHandoffs(now = Date.now()): void {
+  const validNow = asDateTimestampMs(now);
+  if (validNow === undefined) {
+    return;
+  }
   for (const [id, record] of handoffs) {
-    if (record.expiresAt <= now) {
+    if (!isFutureDateTimestampMs(record.expiresAt, { nowMs: validNow })) {
       appendTalkHandoffRoomEvent(record, {
         type: "session.closed",
         payload: { reason: "expired", handoffId: id, roomId: record.roomId },
@@ -344,7 +356,7 @@ function resolveTalkHandoffAccess(
   if (!record) {
     return { ok: false, reason: "not_found" };
   }
-  if (record.expiresAt <= Date.now()) {
+  if (!isFutureDateTimestampMs(record.expiresAt)) {
     appendTalkHandoffRoomEvent(record, {
       type: "session.closed",
       payload: { reason: "expired", handoffId: id, roomId: record.roomId },