// Koru Standard Library: the `explain` part of store — joined via
// `~part explain` in store.kz; members land in koru_store.
//
// A store's truth is scattered: `std/store:new` declares columns and
// interceptor arms, `std/store:insert`/`query`/`take`/`clear`/`stripe`
// sites reference it by name, standing watches ride the bare
// `std/store(name)` form, and `! step`/`! wait` turn the store into a
// pump participant exposing `<s>-step`/`<s>-live`/`<s>-wait`. The
// explainer folds the sites — the member block through the same
// `struct_literal.parseFields` the transform calls — and reports the
// composition: capacity, columns, interceptors, site counts, pump verbs,
// member-proto facets (refine's own `metFields` fold), and each query
// site's plan — index routing decided by the transform's own fold (SPlan).
//
// The site fold lives in `sites` (SX), the plan fold in `plan` (SPlan).
//
// @retain: explain_store_event is referenced from generated code
// (koruc's koru_explain_gather invokes every discovered [explainer]).
~[comptime|explainer] pub tor explain-store {
    program: std/compiler:*const Program,
    allocator: std.mem.Allocator
} -> ExplainReport