`resolve_markdown_mentions` linked any bare, parenthesis-less code span to
the corpus's single `_callable` carrying that label, and methods qualify.
A prose word in a code span (`redis` the server, `data`, `message`) then
became `heading --references--> SomeClass.word()` at INFERRED 0.95, on a
method that has nothing to do with the sentence. On the reporter's corpus
44 of 1,906 mention edges were words of this kind.
A bare single-name span is now resolved in three passes. Explicit evidence
(a cited path, a dotted qualifier chain, or a trailing `()`) resolves as
before. Bare mentions that do not name a method keep resolving, and their
targets are recorded per document. A bare mention that names a method is
kept only when its owner class is already cited in the same document, so
`redis` no longer links to `Cache.redis` while `successWithWarnings` next
to `HandlerResult` still does. Ambiguity, built-ins and the case-sensitive
label match are unchanged.
Tests cover the issue repro, the owner-cited case, the `()` case, a free
function, and the cross-document guard.