fix: harden booking and meeting flows

lib/booking/transaction.ts

@@ -0,0 +1,17 @@
+import { commitTransaction, createLocalReq, initTransaction, killTransaction, type Payload, type PayloadRequest } from "payload";
+import { acquireBookingDayLock } from "./lock";
+
+export async function withBookingTransaction<T>(payload: Payload, key: string, action: (req: PayloadRequest) => Promise<T>): Promise<T> {
+  const req = await createLocalReq({}, payload);
+  try {
+    if (!await initTransaction(req)) throw new Error("Booking transaction unavailable");
+    await acquireBookingDayLock(req, "booking-calendar");
+    await acquireBookingDayLock(req, key);
+    const result = await action(req);
+    await commitTransaction(req);
+    return result;
+  } catch (error) {
+    await killTransaction(req);
+    throw error;
+  }
+}