`confidence` means two different things, and its type docs cite fields PT9 never sends

Two problems in one field's story — one semantic, one documentation.

1. confidence is claimed twice

PT9 import spends AnalysisLink.confidence on anchor ambiguity: confidence: 'low' marks a record whose token placement was a guess among equal folded forms (analysisMerger.ts:339, :406).

#254 proposes spending it on approval provenance — stamping a bulk-approved link lower than a hand-approved one, so "approved" doesn't collapse "a human read this" with "a human swept a hundred of these" (#254's Confidence bullet, which relates it to #51 and #53, never to PT9). #51 is on hold as of 2026-08-25, so #254 is the live claimant.

Two different meanings for one per-assignment field, and neither issue records the collision. Decide which meaning confidence carries, and what mechanism the loser gets — a separate field, a flag on the link, or nothing.

Note the import use is already shipped and sitting in persisted data, so changing its meaning is a migration question, not only a naming one.

2. The type docs cite fields the format never sends

interlinearizer.d.ts:970 still says Paratext status / confidence are "inferred from InterlinearLexeme.IsGuess and .Score". The PT9 interlinear data we consume has neither — no IsGuess, no Score, only VerseData.Hash — and the shipped code means something else by both: status comes from Hash plus Excluded plus the merger's demotion rules, confidence from anchor ambiguity as above.

The doc points at a source that does not exist, for a field whose real meaning is question 1. Fix it once 1 is decided, rather than twice.

Size: S — a decision plus a doc fix; larger if the decision forces a new field.
Priority: P2 — nothing is broken for a user today, but #254 cannot stamp anything until this is settled.

Drafted by Claude

Start with src/types/interlinearizer.d.ts:970 and the PT9 import uses at analysisMerger.ts:339 and :406, then review the linked confidence discussion in #254. Determine and document one meaning for confidence, define what happens to the other meaning, and update the type documentation to match the shipped PT9 fields; account for persisted-data migration if the field meaning changes.