### wai-quantum: a person's taste, learned from their own choices between equals

Feature 10 of the co-design report: a personal, plural taste model.

- **The model** (`engine::taste`):
  - a choice is recorded only when the engine proves the two programs the same circuit (`equiv::equivalent_programs`) or the same state (`equiv::same_state`), by a proof and never by random inputs alone: it is about taste, never correctness;
  - a Bradley–Terry logistic over differences of features the engine measures (gates, two-qubit gates, depth, two-qubit depth, T gates, modelled error) and of the program's text (statements, kinds of gate, repetition, comments), fitted with a ridge penalty by Newton's method, so the same choices give the same weights on every host; a feature that barely varied over the choices is scaled by a floor on its spread, so it cannot turn a large difference between candidates into certainty;
  - the rubric's parts (economy, clarity, insight, precision, utility): each learned from the choices that name it, and a ranking says where a part, or the cost, puts another first;
  - profiles are personal and plural, by name, and never pooled;
  - typicality (one less the novelty of `engine::novelty`) is shown beside each ranking and never learned; the novelty dial (−1 to 1) blends the order by taste with the order by novelty, each standardised over the candidates, so at either end the order is by novelty alone;
  - measured: how many of its own choices a profile predicts, each from the ones before it and each held out from the rest (over the last 100), the choices nothing measured separates, and whether a ranking's first three are built more alike than the first three by cost;
  - `next`: the pair the profile is least sure of that the engine proves equal.
- **The command line:** `wai-quantum taste choose | show | rank | next`, over files or a specification's elites (`--spec`), the profiles in `quantum-taste.json` beside the user's key.
- **For agents:** `taste_rank` and `taste_next` read the person's profile. No tool records a choice: only the person chooses.
- **The Studio:** "Your taste" in the Workbench (Compare two, with the part a choice was about; Rank by my taste, with each one's typicality and the dial; profiles by name). An alternative that is the same circuit as the draft, taken whole or refused whole, is a choice, and Improve orders its candidates by the profile.
- **For hosts:** `taste::call`, `engine_taste` in the page and `taste` in the desktop app.
- **CI:** wai-web's native engine tests count 11.

