add guard to initialization

addMetadata.ts

@@ -3,6 +3,13 @@ import { group, opinion, zone, province } from "./src/schema.ts";
 import { Groups, Opinions, Provinces, Districts } from "./initialData.ts";
 
 async function main() {
+  const isInitialized = await db.query.group
+    .findMany()
+    .then((groups) => groups.length > 0);
+  if (isInitialized) {
+    console.log("Already initialized");
+    return;
+  }
   let groupValues = Groups.map((group) => ({ name: group }));
   await db.insert(group).values(groupValues);
   let opinionValues = Opinions.map((opinion) => ({