feat: Implement graphical student ID card generation for user profiles.

src/modules/class/class.service.ts

@@ -25,7 +25,12 @@ export const classService = {
         };
         return tx ? await execute(tx) : await DrizzleClient.transaction(execute);
     },
-
+    getClassBalance: async (classId: bigint) => {
+        const cls = await DrizzleClient.query.classes.findFirst({
+            where: eq(classes.id, classId),
+        });
+        return cls?.balance || 0n;
+    },
     modifyClassBalance: async (classId: bigint, amount: bigint, tx?: any) => {
         const execute = async (txFn: any) => {
             const cls = await txFn.query.classes.findFirst({