feat(config): wire prodMigrations for auto-migrate on prod boot

Import the migrations array from src/migrations/index.ts and pass it as prodMigrations to the postgres adapter. Per @payloadcms/db-postgres connect.js, when NODE_ENV=production the adapter now auto-runs payload migrate against this array on every boot, so pending migrations apply on deploy without a manual docker exec step. Idempotent on next prod boot since payload_migrations already tracks batches 1-2. DEPLOYMENT.md §7's manual 'docker exec ... payload/bin.js migrate' still works as a fallback via filesystem discovery.

src/payload.config.ts

@@ -43,6 +43,7 @@ import { MarketListings } from "@/collections/market/MarketListings";
 import { MarketNegotiations } from "@/collections/market/MarketNegotiations";
 import { UserNotifications } from "@/collections/users/UserNotifications";
 import { Tickets } from "@/collections/tickets/Tickets";
+import { migrations } from "./migrations";
 import { nodemailerAdapter } from "@payloadcms/email-nodemailer";
 import nodemailer from "nodemailer";
 
@@ -146,6 +147,7 @@ export default buildConfig({
       connectionString: process.env.DATABASE_URI || "",
     },
     push: process.env.NODE_ENV === "development",
+    prodMigrations: migrations,
   }),
   sharp,
   bin: [