SearchReason - temper

Why a search result set is shaped as it is — the load-bearing signal for agents, which
otherwise cannot tell "rephrase the query" from "this tool can never see that content"
(issue #360). Ok ⇒ at least one hit. NoMatch ⇒ a non-empty scope with zero hits
(rephrase / broaden). OutOfScope ⇒ the scope selector resolved to zero candidates —
structurally unreachable content (e.g. wayfind over content that is context-homed in no
cogmap); a different query phrasing will never help.