fix(frontend): psql demo expects integers as a key (#958)

frontend/src/lib/script_helpers.ts

@@ -139,7 +139,7 @@ export const POSTGRES_INIT_CODE = `import {
 //PG parameterized statement. No SQL injection is possible.
 export async function main(
   db: Resource<"postgresql"> = "$res:g/all/demodb",
-  key: string,
+  key: number,
   value: string,
 ) {
   const query = await pgSql(