xfail(reify): examples/0614-comptime-reify-enum — reify a flat enum

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.

current/CHECKPOINT-REIFY.md

@@ -4,7 +4,15 @@ Companion to [PLAN-REIFY.md](PLAN-REIFY.md). Update after every step (one step a
 time, per the cadence rule).
 
 ## Last completed step
-**Phase 0.0 (lock).** Added the comptime type-metaprogramming surface as the
+**Phase 0.1 (xfail).** Added `examples/0614-comptime-reify-enum.sx` — reify a
+flat enum (`value: i64`, `closed`) from a `TypeInfo` literal, construct
+`E.value(3)` / `E.closed`, match both. Seeded an EMPTY
+`expected/0614-…​.exit` marker → corpus is RED ("unparseable expected exit",
+reify still bails). This is the deliberate xfail; **Phase 0.2 turns it green**
+(per the no-commit-both-adds-and-passes cadence). `zig build test` is RED on
+this commit by design (1 example fails); the very next commit makes it pass.
+
+### (prior) Phase 0.0 (lock). Added the comptime type-metaprogramming surface as the
 on-demand module `library/modules/std/meta.sx` (NOT the prelude — see decision
 below): `EnumVariant`/`EnumInfo`/`TypeInfo` data types + bodyless `#builtin`
 decls `reify` / `type_info` / `field_type`. Each builtin bails LOUDLY when

examples/0614-comptime-reify-enum.sx

@@ -0,0 +1,29 @@
+// REIFY Phase 0: mint a NEW nominal enum from a `TypeInfo` value at comptime,
+// then construct one of its variants and match on it — exercising that a
+// reify'd enum (with NO backing AST decl) flows through enum codegen unmodified
+// (layout / construct / match), Contract 2.
+//
+// The enum has two variants: `value` carrying an i64 payload, and `closed` with
+// no payload (`payload = void`).
+#import "modules/std.sx";
+#import "modules/std/meta.sx";
+
+E :: reify(.`enum(.{ variants = .[
+    EnumVariant.{ name = "value",  payload = i64  },
+    EnumVariant.{ name = "closed", payload = void },
+] }));
+
+main :: () -> i32 {
+    e := E.value(3);
+    if e == {
+        case .value: (v) { print("value {}\n", v); }
+        case .closed: { print("closed\n"); }
+    }
+
+    c := E.closed;
+    if c == {
+        case .value: (v) { print("value {}\n", v); }
+        case .closed: { print("closed\n"); }
+    }
+    return 0;
+}