fix legacy code #2

web/lib/discord.ts

@@ -108,10 +108,8 @@ export async function checkBetaServer(guildIds: string[]): Promise<boolean[]> {
 
         if (safeGuildIds.length === 0) return guildIds.map(() => false);
 
-        // Manually construct JSON to preserve u64 precision (native JS numbers lose precision > 2^53)
-        // We want: { "guild_ids": [123, 456] }
-        // checkBotMembership also does this manual construction for the same reason.
-        const body = `{"guild_ids": [${safeGuildIds.join(",")}]}`;
+        // Use JSON.stringify which matches the backend expectation of strings
+        const body = JSON.stringify({ guild_ids: guildIds });
 
         const response = await fetch(`${process.env.BOT_API_URL}/api/is_beta_server`, {
             method: "POST",