Add DOT/FMCSA compliance checker API

GET /api/v1/dot/lookup?dot=XXXXXX — live compliance check combining
local census data + FMCSA QCMobile API. Checks:
- Operating status (allowed to operate Y/N)
- MCS-150 biennial update (overdue detection)
- Insurance filing (BIPD, cargo, bond)
- Safety rating (S/C/U)
- Operating authority status
- Out-of-service rates vs national average
- Crash record

GET /api/v1/dot/search?name=Acme — name search against local census

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/src/index.ts

@@ -46,6 +46,7 @@ import portalRmdReviewRouter from "./routes/portal-rmd-review.js";
 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";
 
 const app = express();
 
@@ -116,6 +117,7 @@ app.use(fccFilingsRouter);
 app.use(foreignQualRouter);
 app.use(pucRouter);
 app.use(fccCarrierRegRouter);
+app.use(dotLookupRouter);
 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()