The previous fix capped OR-mode at top-5 longest tokens which made
the long brain-tech query fast (118s → 13s) but lost the synonym
retrieval that surfaced Telepathy / Neurotechnology — those titles
weren't reachable via the original query tokens alone.
Fix: pass synonym-expanded tokens to the OR-mode fallback as
``extra_or_tokens``. The merged pool keeps the top-5-longest cap so
retrieval cost is unchanged, but long synonym tokens like
"neurotechnology" (15 chars) and "neuroimaging" (12 chars) now beat
shorter query tokens like "thoughts" (8) by length & surface the
right titles.
OR pool example for the brain-tech query:
Pre-synonym: reconstruct, technology, understand, available, thoughts
Post-synonym: consciousness, neuroimaging, clairvoyance, compensation, reconstruct
→ 3/5 brain-tech terms surface naturally in OR-mode.
AND mode stays unchanged (synonyms in AND would relax the strict-
relevance constraint & pull in noise — wrong tradeoff). The
synonym signal flows ONLY into OR-mode-fallback.
Live verified on the 19-token brain-tech query:
- 13s total (Hermes 6-8s + retrieval ~1s + verify ~2s)
- 2/2 verified pairs
- Cited Functional neuroimaging E5 + FreeSurfer E9 (both real
brain-tech corpus sources, not Universal-pragmatics nonsense)
`_search_corpus` recomputes synonym_expand(qtokens) once into
`or_synonym_pool` (caches in concepts.query._CACHE after first
shard); each shard's FTS5Backend.search() receives the same set
through `extra_or_tokens=`. Cost stays sub-second per shard.
Tests: 641 passed (no regression).
russell@unturf.com
2f7132b9ec