comptime VM: Phase 3 — field-level reflection readers

Three more read-only compiler-API readers on the TypeId-handle shape, each backed
by a new TypeTable query that both the legacy handler and the VM call (no drift):

  type_nominal_name(t: TypeId) -> StringId     (nominalName; loud-bail for unnamed types)
  type_field_name(t: TypeId, idx: i64) -> StringId   (memberName)
  type_field_type(t: TypeId, idx: i64) -> TypeId     (memberType)

All loud-bail on out-of-range idx / no-member — no silent default. First multi-arg
compiler fns (callCompilerFn now reads arg 1 = idx); added Vm.argHandle/argTypeId
range-checked arg readers and moved find_type/type_field_count onto them. Names use
the type_* family to avoid colliding with the std metatype builtins (field_name /
type_name in core.sx); the new TypeTable.nominalName is distinct from the existing
typeName(id) display-string renderer.

Example 0629 reflects Pair { lo: Point; hi: Point } — each field name + the nominal
name of a field's type, #run-folded, VM-HANDLED natively. VM unit test added.

Parity 690/690 (gate OFF and -Dcomptime-flat).

current/PLAN-COMPILER-VM.md

@@ -275,13 +275,27 @@ host through it:
     marker (see CLAUDE.md REJECTED PATTERNS — a dedicated sentinel is the required shape),
     so the caller checks the handle against 0. This keeps the reader a clean scalar mirror
     of `intern`/`text_of` and defers `.any`/optional plumbing to when it's actually needed.
-- **Next (P3.2):** more read-only readers on the same `TypeId`-handle shape (`type_name(t)
-  -> StringId`, `field_name(t, i) -> StringId`, `field_type(t, i) -> TypeId`, kind queries),
-  then `register_struct` (the first MUTATING fn — mints a `TypeId`; resolve the mutable-table
-  / host-ABI-vs-target-ABI boundary deliberately, per the open questions). Re-expressing
-  `declare`/`define`/`type_info` as sx (the metatype, which runs at LOWERING time) still
-  needs the VM hardened against malformed lowering-time IR first — keep that on the legacy
-  path until then (see the resume note in CHECKPOINT-COMPILER-API.md).
+- **(P3.2) Field-level reflection readers — `type_nominal_name` + `type_field_name` +
+  `type_field_type` (DONE).** Three more readers on the same `TypeId`-handle shape (each
+  backed by a new `TypeTable` query that BOTH the legacy handler and the VM call, so no
+  drift): `type_nominal_name(t: TypeId) -> StringId` (`nominalName` — a named type's own
+  name; loud-bail for unnamed types), `type_field_name(t: TypeId, idx: i64) -> StringId`
+  (`memberName` — struct/union/tagged-union field, enum variant, named-tuple element), and
+  `type_field_type(t: TypeId, idx: i64) -> TypeId` (`memberType` — struct/tuple/array/vector
+  member type). All loud-bail on out-of-range idx / no-member (no silent default). These are
+  the first MULTI-ARG compiler fns (the VM's `callCompilerFn` now reads arg 1 = idx); added
+  `Vm.argHandle`/`argTypeId` helpers (range-checked u32/TypeId arg reads). Naming uses the
+  `type_*` family so nothing collides with the std metatype builtins (`field_name`/`type_name`
+  exist in `core.sx`). Example `0629` reflects `Pair { lo: Point; hi: Point }` — reads each
+  field name and the nominal name of a field's type, all folded at `#run`, all VM-HANDLED
+  natively. Parity **690/690** (gate ON and OFF); VM unit test added.
+- **Next (P3.3):** `register_struct` (the first MUTATING fn — mints a `TypeId`; resolve the
+  mutable-table / host-ABI-vs-target-ABI boundary deliberately, per the open questions),
+  plus any remaining read-only readers needed to re-express the metatype (kind query,
+  `field_value_int` for enums). Re-expressing `declare`/`define`/`type_info` as sx (the
+  metatype, which runs at LOWERING time) still needs the VM hardened against malformed
+  lowering-time IR first — keep that on the legacy path until then (see the resume note in
+  CHECKPOINT-COMPILER-API.md).
 
 ### Phase 3 — Compiler-API on flat memory (resume the stream — no weld)
 With native-byte comptime values, re-home the compiler-API: