save_post_file is now async and gains an optional
category_fetcher parameter. When the template uses any category
token (%artist%, %character%, %copyright%, %general%, %meta%,
%species%) AND the post's tag_categories is empty AND a fetcher
is available, it awaits ensure_categories(post) before calling
render_filename_template. This guarantees the filename is
correct even when saving a post the user hasn't clicked
(bypassing the info panel's on-display trigger).
When the template uses only non-category tokens (%id%, %md5%,
%score%, %rating%, %ext%) or is empty, the ensure check is
skipped entirely — no HTTP overhead for the common case.
Every existing caller already runs from _run_async closures,
so the sync→async signature change is mechanical. The callers
are updated in the next two commits to pass category_fetcher.
pax
8f8db62a5a