Task — engineering-spec@1

"Lexical retriever leg in brain recall (tsvector + pg_trgm) fused via RRF"

draftTASK-MEMORY-219

module memory · class product · priority p1 · created 2026-07-08 · shipped null
depends on TASK-MEMORY-212 · blocks none

TASK-MEMORY-219: Lexical retriever leg in brain recall (tsvector + pg_trgm) fused via RRF

1. Description

hybrid beats vector-only on golden set; expression indexes in place; degraded modes unchanged

Migrated 2026-07-08 from the memory improvement backlog, folded into the task system as class: improvement. Source report refs: R11, F12.

Acceptance criteria

[ ] hybrid beats vector-only on golden set; expression indexes in place; degraded modes unchanged