refactor: clean up unused imports and dead code across commands, services, and tests.

src/commands/economy/balance.ts

@@ -17,7 +17,7 @@ export const balance = createCommand({
         const targetUser = interaction.options.getUser("user") || interaction.user;
 
         if (targetUser.bot) {
-            return; // Wait, I need to send the reply inside the if.
+            return;
         }
 
         const user = await userService.getOrCreateUser(targetUser.id, targetUser.username);