Two coupled capabilities on the road to the std restructure
(current/PLAN-STDLIB.md, issue 0114):
1. alias.Type.method() / alias.Type as a call head, alias.CONST, and
alias.Enum.variant now resolve — previously only alias.fn() and
type-position alias.Type worked. objectIsValue treats an
alias-rooted field_access as a type head; the call path strips the
alias to the existing Type.method machinery; lowerFieldAccess
resolves alias.CONST pinned to the target module and alias.Enum.x
as a typed enum literal; resolveTypeWithBindings resolves qualified
type_exprs pinned to the target.
2. The carry rule: namespaceAliasTarget resolves an alias from the
file's own edges first, then from DIRECT flat imports (one level),
diagnosing two distinct carried targets as ambiguous. All qualified
shapes work through a carried alias — the std.sx namespace tail
(mem.GPA.init() etc.) is now expressible.
Regression: examples/0831-modules-namespace-alias-carry.sx (direct +
carried, all seven shapes).