client_for_type gains optional db + site_id kwargs. When both are
passed and api_type is gelbooru or moebooru, a CategoryFetcher is
constructed and assigned to client.category_fetcher. The fetcher
owns the per-tag cache, the batch tag API fast path, and the
per-post HTML scrape fallback.
Danbooru and e621 never get a fetcher — their inline JSON
categorization is already optimal.
Test Connection dialog and scripts don't pass db/site_id, so they
get fetcher-less clients with the existing search behavior.
pax
f5954d1387