fix(db): swap @neondatabase/serverless for postgres.js (local dev support)

Neon serverless driver requires remote WebSocket — incompatible with local
PostgreSQL. Replaced with postgres.js (drizzle-orm/postgres-js) in db/index.ts,
scripts/seed.ts, and drizzle.config.ts.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

teressa-copeland-homes/package.json

@@ -13,12 +13,12 @@
     "db:studio": "drizzle-kit studio"
   },
   "dependencies": {
-    "@neondatabase/serverless": "^1.0.2",
     "@vercel/blob": "^2.3.1",
     "bcryptjs": "^3.0.3",
     "drizzle-orm": "^0.45.1",
     "next": "16.2.0",
     "next-auth": "5.0.0-beta.30",
+    "postgres": "^3.4.8",
     "react": "19.2.4",
     "react-dom": "19.2.4",
     "zod": "^4.3.6"