增加支付逻辑

backend/README.md

@@ -77,6 +77,20 @@ docker build -f backend/Dockerfile.runtime \
 ```
 
 The runner defaults to `CGO_ENABLED=0` for reproducible cross-platform builds.
+When adding a SQL migration, run `npm run db:bundle` at the repository root and
+commit the resulting Go migration bundle before building any backend image.
+The image uses the existing `backend/` build context and needs no Node/npm at
+runtime. In the ACK template, `DATABASE_AUTO_MIGRATE=true` runs unapplied
+bundled migrations with `DATABASE_MIGRATION_URL` before the HTTP server
+listens. `DATABASE_APP_ROLE` names the application database user to grant;
+`DATABASE_MIGRATION_TIMEOUT_SECONDS` defaults to 180. Other deployments leave
+automatic migration disabled unless explicitly configured. See
+[`../docs/DEPLOYMENT.md`](../docs/DEPLOYMENT.md) for Secret and rollout details.
+The migration and application URLs must target the same database host, port,
+and database name; their usernames may differ. ACK/Compose inject environment
+variables into Go. When starting `go run` or the binary directly, explicitly
+export the database startup variables; `.env.local` alone does not supply them.
+
 To exercise the backend locally, listen on port 8080 and route browser API
 requests there with a same-origin development proxy: