fix: map custom Prisma model names to Better Auth schema

src/lib/auth.ts

@@ -5,6 +5,13 @@ import { db } from './db';
 export const auth = betterAuth({
   database: prismaAdapter(db, {
     provider: 'postgresql',
+    // Map our custom table names to Better Auth models
+    schema: {
+      user: 'auth_user',
+      session: 'auth_session',
+      account: 'auth_account',
+      verification: 'auth_verification',
+    },
   }),
   emailAndPassword: {
     enabled: true,