Removes the asyncio.create_task(prefetch_batch) calls from
search() and get_post() in both clients. Tags are now fetched
ONLY when the user actually clicks a post (via ensure_categories
in the info panel path) or saves with a category-token template.
The background prefetch was the source of most of the complexity:
probe timing, early-exit bugs from partial composes racing with
on-click ensures, Rule34's slow probe blocking the prefetch
window. All gone.
New flow:
search() → fast, returns posts with flat tags only
click → ensure_categories fires, ~200ms HTML scrape or
batch API, categories arrive, signal re-renders
re-click → instant (cache compose, no HTTP)
save → ensure in save_post_file, same path
The ~200ms per first-click is invisible during the image load.
The cache compounds across posts and sessions. The prefetch_batch
method stays in CategoryFetcher for potential future use but
nothing calls it from the hot path anymore.
pax
35424ff89d