#22054: fix(auto-reply): Hide message_id and sender metadata in direct chats

Direct chats do not require moderation tracking or complex group threaded history, but this untrusted metadata visibly leaks into the standard DM UI. This change strictly hides this metadata in `isDirect` conversation info context, resolving UI clutter. Tests have been updated to reflect the new behavior. <!-- greptile_comment --> <h3>Greptile Summary</h3> Hides `message_id`, `conversation_label`, and `sender` fields in direct chat contexts to prevent untrusted metadata from cluttering the DM UI. Tests updated to verify these fields remain visible in group chats. **Issues found:** - `message_id_full` field is not hidden in direct chats, allowing metadata to leak when it differs from `message_id` <h3>Confidence Score: 2/5</h3> - This PR has a logic bug that allows metadata to leak in direct chats - Score reflects incomplete implementation - `message_id_full` field is not properly hidden in direct chats, violating the stated goal of preventing metadata leakage in DM UI - Pay close attention to `src/auto-reply/reply/inbound-meta.ts:81-82` where the `message_id_full` logic needs the `isDirect` check _{Last reviewed commit: f708dfc} <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->