After a leading `.` (enum literal `.enum`, field access `x.enum` /
`E.struct`, match arm `case .enum:`) a reserved keyword is unambiguously
the member/variant NAME — the dot rules out the keyword reading — so no
backtick escape is needed. A declaration of such a variant still needs
the backtick (enum { `enum: i64 }), since the decl site has no dot.
Adds Parser.dotMemberName() (identifier OR identifier-shaped keyword)
and routes the leading-dot enum-literal and postfix field-access sites
through it. readme updated. The reify example 0614 now uses the cleaner
reify(.enum(...)) spelling (still xfail — reify lands next commit).
REIFY Phase 0.1. Add the end-to-end Phase-0 example: reify a flat enum
(value: i64, closed) from a TypeInfo literal, construct E.value(3) /
E.closed, and match both arms. Seed an empty expected/*.exit marker.
RED by design (reify still bails -> "unparseable expected exit"); the
next commit (0.2) implements reify and turns it green. Satisfies the
no-commit-both-adds-a-test-and-passes cadence.
