Search a subreddit

Automatically search a subreddit on reddit.com. Search posts within a single subreddit, with optional sort, time window, and date cutoff. Returns subreddit, count, and threads (each with id, url, title, author, score, num_comments, created, subreddit, nsfw, preview_text). `limit` is a maximum, not a guarantee: a search with fewer matches returns what exists, and a search with none returns count 0. With `sort=new`, pass `since` (an ISO date or shorthand like "7d") to leave out results older than that cutoff. When a query has no genuine matches, Reddit's own search sometimes returns a few loosely related posts from the subreddit instead of an empty result, with no way to tell them apart from real hits. Reddit's subreddit-scoped search cards show titles only, so preview_text is null here; for body excerpts use reddit.com/search_reddit with a `subreddit:name` term in the query.