green(reify): type-fn bodies comptime-evaluated; reify fully removed from the compiler

Second slice of the re-architecture — the compiler now has ZERO type-
construction code beyond declare/define.

- instantiateTypeFunction: a type-fn body returning a computed Type (a call
  to a non-generic, bodied, Type-returning fn) is comptime-evaluated with the
  type bindings active, then renamed to the mangled instantiation name for
  identity (renameNominalType). Replaces the old reify-call pattern-matching.
- DELETED: reifyType (lower/nominal.zig), findReturnReifyCall (lower/generic.zig),
  and the stale inline-position reify gate in resolveTypeCallWithBindings.
- evalComptimeType (was evalComptimeTypeNamed): pure eval, no rename; the
  type-fn caller renames explicitly. renameReifiedType → renameNominalType.
- The TYPE NAME now travels in the data: EnumInfo gains `name`, and define()
  names the slot from it (the compiler derives no name from a binding LHS).
  examples/0614/0615 carry `name = "..."`; RecvResult/TryResult set it too.
- field_type stays a reflection #builtin (reads a type); only construction
  moved out. All reify mentions stripped from compiler source.

examples 0614/0615/0617 run on the floor. Full suite green (673).

examples/0614-comptime-reify-enum.sx

@@ -8,7 +8,7 @@
 #import "modules/std.sx";
 #import "modules/std/meta.sx";
 
-E :: reify(.enum(.{ variants = .[
+E :: reify(.enum(.{ name = "E", variants = .[
     EnumVariant.{ name = "value",  payload = i64  },
     EnumVariant.{ name = "closed", payload = void },
 ] }));

examples/0615-comptime-reify-typefn-identity.sx

@@ -9,7 +9,7 @@
 #import "modules/std/meta.sx";
 
 Box :: ($T: Type) -> Type {
-    return reify(.enum(.{ variants = .[
+    return reify(.enum(.{ name = "Box", variants = .[
         EnumVariant.{ name = "some", payload = T    },
         EnumVariant.{ name = "none", payload = void },
     ] }));