tools/sizelint + CLAUDE.md rule 13: gate hardcoded size literals

Drew's Hare-discipline framing: "no hardcoded size literals anywhere in
the compiler." This session spent 32 commits sweeping after-the-fact
and STILL kept introducing new bypass sites in our own structural
work (A.5's tupleelemslot/fieldslotsize most recently). The cure is a
gate that catches new violations at commit time, not a deeper sweep.

tools/sizelint (sh+gawk):
- Always-on: `.size = NN` / `->size = NN` / `prim(...,"name",NN,...)`.
- Context-gated literals (NN(u64|i64) and `return NN`) in files or fns
  matching size|slot|elem|field|stride|paramfield|tinfo|primtype|
  slotsize|letemit|tagged.
- Allow-list via `// sizelint-ok: <reason>` or `/* sizelint-ok: ... */`.
- Comment strip happens after allow-list match so prose mentions of
  16/24 stay quiet.

Makefile: `test: all sizelint $(TESTS)` so the gate runs before any
binary builds.

CLAUDE.md rule 13 documents the discipline + escape hatch + optional
pre-commit-hook symlink.

Audit caught 3 real cstage bugs (cmd/wcc/check.c resolve_type:1002,
1079, 1531 hardcoded `tt->size = 16` / `= 32` for tagged-with-ptr and
tagged-with-slice payloads — should read `8 + sub.size`). Fixed
inline; behavioral no-op today (pt->size=16, st->size=24, sub.size=24
match the prior literals) but the SSoT seam carries forward through
#1/#34/#65.

8 SSoT-seed allow-lists added (cstage type.c ty_str/ty_slice prim
factories; wwstage primtypesize/tyslicesize; lib/ww/typ.ww tystr +
slice fields + their main.combined.ww mirrors). One amalloc-overalloc
allow-list at lib/ww/typ.ww:273 cites pending #36 (typed amalloc).

#66 filed for extending the filter once #65 routes lib/bytes +
lib/getopt's sizeof(slice) / sizeof(option) literals through SSoT —
naive line-pattern extension would false-positive on 22+ ELF wire-
format sites in dynout.ww.

131/131 + 994 + 995 + bootstrap green with `make sizelint` exit 0.

cmd/wcc/type.c

@@ -61,7 +61,7 @@ typesinit(Arena *a)
 	ty_f32    = prim(a, TY_F32,    "f32",     4, 4);
 	ty_f64    = prim(a, TY_F64,    "f64",     8, 8);
 	/* str is { *u8, len } — 16 bytes on amd64. ABI: pointer + u64. */
-	ty_str    = prim(a, TY_STR,    "str",    16, 8);
+	ty_str    = prim(a, TY_STR,    "str",    16, 8); /* sizelint-ok: SSoT for ty_str (#64) */
 	ty_err    = prim(a, TY_ERR,    "<err>",   0, 1);
 	ty_never  = prim(a, TY_NEVER,  "never",   0, 1);
 	/* #29: predeclared `type nomem = !void;`. NAMED so variant_match
@@ -98,7 +98,7 @@ type_slice(Arena *a, Type *sub)
 {
 	Type *t = newtype(a, TY_SLICE);
 	t->sub = sub;
-	t->size = 24;	/* { *T, len, cap } */
+	t->size = 24;	/* { *T, len, cap } */	/* sizelint-ok: SSoT for ty_slice (#64) */
 	t->align = 8;
 	return t;
 }