comptime VM: flip Type to .type_value; migrate the .any refs that mean a Type value

type_resolver "Type" -> .type_value; const_type result + emitConstType now a
bare 8-byte i64 handle (not a 16-byte Any box). Migrated every .any ref meaning
"a Type value", leaving real boxed-Any refs:

- "Any holds a Type" meta-marker tag .any -> .type_value at all 4 consumers
  (reflectArgTypeId, reflectTypeId, the comptime type_tag-as-struct path,
  resolveTypeCategoryTags "type").
- reflection-builtin return types (type_of/declare/define) -> .type_value;
  runtime type_of(any) reads the tag as a .type_value (no re-box).
- expr_typer: a bare type-name expr is .type_value (backtick is_raw exempt).
- reflectionArgIsType accepts .type_value OR .any (a reflection arg can be a
  bare Type or a boxed Any).
- comptime switch_br accepts a .type_tag discriminant (type-category match).
- a bare function name in a Type slot -> const_type(its function type), not a
  func-ref (fixes a JIT crash); old string-box kept only for genuine Any params.
- field-not-found diagnostic + formatTypeName render .type_value as "Type".

Fixed 3 unit tests asserting the old .any behavior. 697/0 both gates (gate ON
bails cleanly to legacy since the VM doesn't model Type values yet) + 494 unit
tests. 24 snapshots regenerated (22 .ir const_type shape; 2 .stderr Any->Type).

src/ir/calls.zig

@@ -154,7 +154,7 @@ pub const CallResolver = struct {
                 return refl(bare_name, self.l.module.types.findByName(self.l.module.types.internString("TraceFrame")) orelse .unresolved);
             if (std.mem.eql(u8, bare_name, "is_flags")) return refl(bare_name, .bool);
             if (std.mem.eql(u8, bare_name, "type_is_unsigned")) return refl(bare_name, .bool);
-            if (std.mem.eql(u8, bare_name, "type_of")) return refl(bare_name, .any);
+            if (std.mem.eql(u8, bare_name, "type_of")) return refl(bare_name, .type_value);
             if (std.mem.eql(u8, bare_name, "field_value")) return refl(bare_name, .any);
             // Plain bare same-name flat collision (R5 §C): route through the ONE
             // author producer `selectedFreeAuthor` so `plan` types the call as the