Search a subreddit

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. With `sort=new`, pass `since` (an ISO date or shorthand like "7d") to filter out results older than that cutoff — useful for searching a subreddit for recent activity by date rather than by relevance/rank. When a query has no genuine matches, Reddit's own search sometimes silently returns a small number of loosely-related posts from the subreddit instead of an empty result, with no way to tell them apart from real hits — a non-zero count doesn't guarantee relevance. Reddit's subreddit-scoped search cards show titles only, with no body excerpt, so preview_text is null here on every sort; that is the surface, not a limitation of the script. To get per-subreddit results that include body excerpts, use reddit.com/search_reddit with a `subreddit:name` term in the query. Reddit caps each page at 100 results, so paginate with the after cursor to go beyond that.