claude@clouddev1
a50c6cdf70
Adds tests/typing_surface/where_expression.rs — 9 matrix cells for the complex WHERE / show-data limit typing surface: operator candidates after an operand, AND / OR after a predicate, NOT, BETWEEN / IN bounds, and `show data` where / limit. Writing the cells surfaced a grammar bug. `predicate_tail`'s `[NOT] negatable` branch started with `Optional(not)`, and an Optional-first `Seq` always "commits" — so on an incomplete input the walker's `Choice` returned that branch's `Incomplete` early and discarded every sibling branch's expected set, dropping `is` and the comparison operators from completion after a column. Fixed by splitting it into explicit `NOT negatable` and bare `negatable` branches — no `predicate_tail` branch starts with an `Optional` now. The matched terminal sequence is unchanged, so `build_expr` is untouched. Docs: ADR-0026 gains an "As-built notes" section recording the option-1 builder realization, its two deviations from the §3 sketch, and the deferral of §7 diagnostic flagging to ADR-0027. requirements.md C5a -> [x] (steps 1-4) with the test baseline refreshed to 1079; CLAUDE.md's deferred list reconciled (C5a implemented; the QA1/QA2 note now points at ADR-0028).