Ground-up replacement for news_triage, whose signal quality failed because it
had no representation of what its user likes -- three keywords fed to BM25 plus
a two-term substring blocklist.
profile/ holds the taste model as prose and TOML: 11 interest blocks, 3 veto
blocks, 5 importance blocks, each a set of probe sentences to be embedded.
The [scoring] constants are fitted, not guessed. CALIBRATION.md records the
measurements against all 3,885 items in the v0.2 database and 40 real feedback
labels, including two findings that changed the design:
- compare blocks by z-score within block, never raw cosine; raw cosine let
geopolitics win 78% of items and buried known-liked items at median rank 1246
of 3885 (293 after normalizing)
- veto needs a margin over the interest signal, not a threshold; a plain 0.55
cutoff falsely killed "Belgian mayor blocks club from hosting Israeli opponent
in Europa League", which the old substring blocklist also killed
