feat(auth): integrate Aliyun SMS verification flow with docs update

Wire auth verification-code delivery to Aliyun SMS with mock fallback, config validation, and a standalone SMS smoke-test script. Update deployment checklist and system status docs with required env vars and rollout notes.

Made-with: Cursor

backend/package.json

@@ -12,6 +12,7 @@
     "prisma:migrate": "prisma migrate dev",
     "prisma:studio": "prisma studio",
     "prisma:seed": "tsx prisma/seed.ts",
+    "test:sms": "tsx scripts/test-aliyun-sms.ts",
     "iit:equery:dedupe": "tsx scripts/dedupe_open_equeries.ts",
     "iit:equery:dedupe:apply": "tsx scripts/dedupe_open_equeries.ts --apply",
     "iit:guard:check": "tsx scripts/validate_guard_types_for_project.ts",
@@ -31,6 +32,8 @@
   "author": "AI Clinical Dev Team",
   "license": "ISC",
   "dependencies": {
+    "@alicloud/credentials": "^2.4.4",
+    "@alicloud/dysmsapi20170525": "^4.5.0",
     "@fastify/cors": "^11.1.0",
     "@fastify/jwt": "^10.0.0",
     "@fastify/multipart": "^9.2.1",