fix(discord-presence): show "PostHog Code" as the preview card title

Match the live presence, whose title comes from the Discord application
name.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: gantoine

apps/code/src/renderer/features/settings/components/sections/DiscordPresencePreview.tsx

@@ -108,7 +108,9 @@ export function DiscordPresencePreview({
           </div>
 
           <Flex direction="column" className="min-w-0 gap-0">
-            <Text className="font-bold text-[15px] text-gray-12">PostHog</Text>
+            <Text className="font-bold text-[15px] text-gray-12">
+              PostHog Code
+            </Text>
             <Text truncate className="text-[13px] text-gray-12">
               {details}
             </Text>