wcc/check: #103/#108 inferred untyped-int defaults to int (8B), both stages

cstage type_default(TY_UNTYPED_INT) returned ty_i32 (4B): an unannotated
`let x = <v>` / `let a = [<v>,..]` silently TRUNCATED any value > 2^31
(5000000000 -> 705032704) and strode inferred arrays at 4. wwstage kept
the element raw untyped_int (size 0), which sized INCONSISTENTLY across
cgen — the array STORE strode the 8 sentinel but letslotsize under-
allocated the frame (SEGV) and cgindex strode the READ at 1. The two
stages were each wrong differently; #263 polarity: cstage was the
truncating side. int = machine word = 8B (Go-style, MEMORY
project_int_machine_word_derived_limits); Hare lowers a flexible iconst
to `int`, never a fixed i32 (ref/harec/src/types.c:835).

Fix, one root, both stages (FUSE — the cs default + the ww concrete
element must land together, else the inferred array is transient cs!=ww):
- cmd/wcc/type.c type_default(TY_UNTYPED_INT) ty_i32 -> ty_int. The
  root; stops scalar AND array truncation at source.
- cmd/wcc/check.c N_ARRLIT empty-elt fallback ty_i32 -> ty_int. Symmetric
  pair; count-0 array emits no stores, so byte-id-neutral.
- selfhost/cmd/wcc/check.ww exprtype N_ARRLIT: default the inferred
  element's untyped flavor to concrete (untyped_int->int, _float->f64,
  _str->str, _rune->rune, _bool->bool, mirror cstage type_default),
  empty-elt "i32"->"int", and stamp the synthesized N_TARRAY's .type_ so
  slotsize / elemsizeofc / letslotsize read its real [N]int size via the
  type table (rule-13) — no letslotsize special-case (SSoT).
combined.ww regen (check.ww embed): w6c + wwdump.

ken v2 corpus re-census (160 files): EXACTLY 5 rows move, ALL CONVERGE
(byte-id YES + run exit 0, none both-wrong, zero regression):
  m2_while   #108 scalar via alias-bool loop
  m8_range1  #104 for-range elem over alias [4]int
  m8_range2  #104 over 2-level alias
  m8_slice1  #103 inferred array + alias-slice init
  m8_slice2  #103 + 2-level-alias slice + re-slice
Bootstrap byte-id neutral (5 combined units w6c==w6c_ww; 0 bare inferred
arrays in selfhost). Annotated controls untouched ([4]i32 stride-4,
[4]int stride-8, byte-id). Pinned in test/wcc/813_arrlit_infer_elem_run
(the 2 direct repros incl the >2^31 truncation teeth + all 5 movers +
controls; test-unit 296).

Closes #103 (inferred-array SEGV + truncation), #108 (cstage scalar
untyped-int truncation), #104 (for-range elem alias i32-stamp), and the
m8_slice []int-init acceptance divergence.

Makefile

@@ -411,6 +411,7 @@ TESTS	= $(BIN)/test_smoke $(BIN)/test_lex $(BIN)/test_parse $(BIN)/test_check \
 	  $(BIN)/test_idx_structlit_store \
 	  $(BIN)/test_inferred_let_struct \
 	  $(BIN)/test_agg_assign_width \
+	  $(BIN)/test_arrlit_infer_elem_run \
 	  $(BIN)/test_placeaddr_store \
 	  $(BIN)/test_tryprop_multisuccess \
 	  $(BIN)/test_append_place \
@@ -1127,6 +1128,15 @@ $(BIN)/test_agg_assign_width: test/wcc/812_agg_assign_width.c \
 		$(LIB)/libwwrt.a | $(BIN)
 	$(CC) $(CFLAGS) -o $@ $<
 
+# #103/#108 (+#104 + m8_slice acceptance): inferred untyped-int → int
+# (8B) default, both stages byte-id. Pins the 2 direct repros (>2^31
+# teeth) + ken v2's 5 named corpus movers + annotated i32/int controls.
+$(BIN)/test_arrlit_infer_elem_run: test/wcc/813_arrlit_infer_elem_run.c \
+		$(BIN)/ww $(BIN)/w6c $(BIN)/w6c_ww $(BIN)/w6a $(BIN)/w6l \
+		$(BIN)/ww_ww \
+		$(LIB)/libwwrt.a | $(BIN)
+	$(CC) $(CFLAGS) -o $@ $<
+
 # F8+F9 (tasks #5/#12, regex fold-2b): `?` interim single-success gate
 # (|success| > 1 loud-rejected on BOTH stages until task #14's
 # subset-union typing) + direct `f()? is T` / `match (f()?)` reject