wcc/check: #62 typedecl layout is decl-order-INDEPENDENT — demand-resolve forward refs + loud cycle guard (#69)

check_file resolved typedecl bodies in file order with an eager
under->size copy, so any body referencing a typedecl declared LATER
read its size-0 placeholder and baked it in: alias size 0, tagged-
union maxsz 0 (the F0 m5_match $48-frame under-allocated box), struct
field offsets collapsed, array element stride 0 — a whole cstage-only
family (7 size()-probe rows, all cs-fail/ww-pass pre-fix). wwstage's
demand-driven tinfofornode was order-independent on every row, so this
aligns cstage UP to the measured runtime-correct side (the #263-era
ruling; rule 10's align-down governs acceptance surface, not layout
correctness). Oracle: ken /tmp/ken_62_oracle.md — union size is 8B tag
+ roundup8(max CHASED member size), a fixed point over the module,
never a function of decl order.

resolve_typename now resolves a referenced-but-unresolved typedecl on
demand via resolve_typedecl (cycle-guarded by Type.resolving); the
pass-1.5 loop funnels through the same helper. No consumer can see an
unresolved placeholder by construction.

CYCLE GUARD — #69 ABSORBED into this rider (rob's rider condition):
true typedecl cycles now LOUD-reject on BOTH stages — "circular type
dependency" — mirroring harec's in_progress check (ref/harec/src/
check.c:4767 "Circular dependency for '%s'"). Pre-guard: cs silently
sized cycles 0; wwstage HUNG on an alias cycle (`type a = b; type
b = a` — ken's hang probe /tmp/ken62/c1_cycle.ww, killed at the 20s
timeout) and stack-overflowed on a struct value cycle. The check sits
at the VALUE-position size consumers only (alias root, struct field,
array elem, tuple member, union member), so the legal pointer
self-ref (`type node = struct { next: *node }`, the io.stream shape)
stays accepted, byte-id. wwstage gets the twin tinfo.resolving flag
(lib/ww/typ.ww) + circularnamed in check.ww; its arm loud-STOPS
(os.exit) rather than accumulating — wwstage's AST-level alias
walkers (resolvealias, aliaslookup chains) follow TNAME->TNAME by
name, blind to the tinfo table, and spin on a cyclic alias graph even
after the table edge is cut to tyerr (measured); cstage accumulates,
its single-peel ternaries cannot loop.

TWO-LAYER SPLIT — this is ONE bug number (#62) deliberately split
across THREE commits (this rider + F1 + F2), per ken's sizes-correct ≠
payload-correct proof: in NORMAL decl order both stages size the box
correctly (16/24, frames $64) yet both still run exit 2 — the box
STORE is word0-only, a chase-blind copy-WIDTH lookup in cgen, NOT the
type table. EXPECTED-FAIL after this commit: m5b_match1/m5_match stay
exit-2 both stages (now byte-id BOTH orders; pre-fix the fwd order was
$48-frame divergent). The Layer-2 sites and destinations:
  - F1 (cstage): cg_widen_tagged_store single NAMED peel,
    cmd/w6c/cgen.c ~2464 — the type_chase_named census family.
  - F2 (wwstage): rhsstructpayload bare name-keyed structlookup, no
    alias chase, selfhost/cmd/wcc/cgenutil.ww:3062 (structlookupchain
    :1691 already exists).
Banked runtime payload-readback rows for F1/F2: /tmp/impl62r_layer2_rows.md.

Test 944_alias_decl_order_size_run: every size class pinned in BOTH
decl orders (sizes, named union, struct field offsets, array elem,
2-level chain — norm + fwd twins, prefix-luck-breaking last-word
readbacks), 3 cycle BUILDERR rows + the legal ptr-self-ref row,
(void|base) no-regress control; dual-stage + per-row byte-id (arrelem
rows byte-id exempt: pre-existing #60 index-over-alias divergence,
order-independent, cited at the rows). lib/ww/typ.ww is an embedded
source: both main.combined.ww regen'd + committed (freshness gate).

lib/ww/typ.ww

@@ -124,6 +124,14 @@ type tinfo = struct {
 				// cstage Type.nullable (cmd/wcc/ww.h:430-433).
 	name:     str,
 	under:    *tinfo,
+	resolving: i32,	// #62/#69: TY_NAMED demand-resolution cycle guard.
+				// Mirrors cstage Type.resolving (cmd/wcc/ww.h)
+				// and harec idecl->in_progress (ref/harec/src/
+				// check.c:4767): set while the alias body
+				// resolves; a VALUE-position read of an
+				// in-progress named is a true type cycle and
+				// loud-rejects. Pointer positions never read
+				// size, so legal self-refs stay accepted.
 	slotsize: u64,	// #61 A.5: stack-slot SSoT split from `size`.
 				// `size` stays natural (Hare-faithful);
 				// `slotsize` carries the slot-padded width