behavior change: a single mid-call network drop could previously
poison _batch_api_works=False for the whole site, forcing every
future ensure_categories onto the slower HTML scrape path. _do_ensure
now routes the unprobed case through _probe_batch_api, which only
flips the flag on a clean HTTP 200 with zero matching names; timeout
and non-200 responses leave the flag None so the next call retries
the probe.
The bug surfaced because fetch_via_tag_api swallows per-chunk
failures with 'except Exception: continue', so the previous code
path couldn't distinguish 'API returned zero matches' from 'the
network dropped halfway through.' _probe_batch_api already made
that distinction for prefetch_batch; _do_ensure now reuses it.
Tests in tests/core/api/test_category_fetcher.py pin the three
routes (transient raise, clean-200-zero-matches, non-200).
pax
bbf0d3107b