Get X tweet

Fetch a tweet by URL — the focal post plus the surrounding conversation. Returns `tweet` (the focal post; null if deleted/tombstoned) and `replies[]`, which holds every other tweet on the conversation page: both the focal's ancestors (the thread above it, present when the focal is itself a reply; each has `in_reply_to` null or pointing above the focal) and the replies below it (`in_reply_to` points at the focal or a sibling reply). Use `in_reply_to` to tell ancestors from replies and rebuild the thread — the array is not filtered to descendants of the focal. Each entry is a canonical tweet record: id, url, author {id, handle, name}, text, created_at, lang, likes, retweets, replies, quotes, bookmarks, views, is_retweet, is_quote, in_reply_to {id, author_handle}. Scrolls the main thread until `count` is met (then complete=false — more may exist) or it drains (complete=true). Replies behind a "Show more replies"/hidden/probable-spam cursor are not expanded, so even complete=true is a floor, not a guarantee every nested reply was seen.