fix(auth): generate UUID ids to match postgres schema

Backend/auth.ts

@@ -18,6 +18,11 @@ export const auth = betterAuth({
       user: schema.users,
     },
   }),
+  advanced: {
+    database: {
+      generateId: 'uuid',
+    },
+  },
   emailAndPassword: {
     enabled: true,
     password: {