post-completion flow: survey, referral program, review ask

- Migration 081: referral_codes, referral_uses, exit_surveys tables
- API: POST /api/v1/survey, POST /api/v1/referral/check, GET /api/v1/referral/:email
- Worker: completion_emails.py — sends completion + 24h follow-up (survey + referral)
- Survey page: /survey/?order=X&rating=N — star rating, feedback, Google review ask
- Referral: REF-FIRSTNAME codes, $25 credit per referred order, no limit
- Low ratings (1-3 stars) trigger Telegram alert for admin follow-up
- Cron: every 15 minutes

api/src/index.ts

@@ -47,6 +47,7 @@ import portalEsignGenericRouter from "./routes/portal-esign-generic.js";
 import pucRouter from "./routes/puc.js";
 import fccCarrierRegRouter from "./routes/fcc-carrier-registration.js";
 import dotLookupRouter from "./routes/dot-lookup.js";
+import surveyRouter from "./routes/survey.js";
 
 const app = express();
 
@@ -120,6 +121,7 @@ app.use(foreignQualRouter);
 app.use(pucRouter);
 app.use(fccCarrierRegRouter);
 app.use(dotLookupRouter);
+app.use(surveyRouter);
 app.use(adminCryptoRouter);
 // Note: identityRouter mounted above express.json() for webhook route,
 // but also handles non-webhook routes (create-session, poll) which work fine with json()