fix new user error + add wrangler.toml examples

backend/database/src/schema.ts

@@ -28,6 +28,7 @@ export const sandbox = sqliteTable("sandbox", {
 	name: text("name").notNull(),
 	type: text("type", { enum: ["react", "node"] }).notNull(),
 	visibility: text("visibility", { enum: ["public", "private"] }),
+	createdAt: integer("createdAt", { mode: "timestamp_ms" }),
 	userId: text("user_id")
 		.notNull()
 		.references(() => user.id),