test: migrate 24 residual carriers into the fixture corpus

Audit-driven migrate-and-retire wave (one read-only auditor per
carrier batch, verdicts row-checked through the full corpus gate):
every retired carrier's assertions are now owned by declarative
fixtures or an existing owner. 238 new fixtures land (corpus 1,239 ->
1,477; cells 2,954), covering enum/str/slice/tagged array elements,
inferred-length arrays, global slice/str zero-init and literals,
global array/pointer field reads and stores, struct-literal slice
fields, struct returns, float arithmetic, size/int limits, sort and
log-vstream behavior, place-addressed stores, and append places.
Rejection rows STRENGTHEN the old nonzero-exit checks to required
diagnostic fragments; all byte-id claims fold into the blanket
test-data-byteid sweep (now 1,142 compared, 0 pinned-divergent).
Four carriers were fully redundant with existing fixtures/lang tests
(749, 722, 765, and 771's byteid rows) and retire without new rows.
Native carriers 171 -> 147 (residual 135 -> 111).

test/wcc/data/r805_read_depth2_idx/case.ww

@@ -0,0 +1,17 @@
+//ww:run-exit 59
+package main;
+type capture = struct { content: str, start: size, end: size };
+type t = struct { pc: size, cap: capture };
+let end: size = 777;
+export fn main() i32 = {
+	let ts: []t = [];
+	append(ts, t { pc = 5, cap = capture { content = "abc", start = 11, end = 13 } });
+	append(ts, t { pc = 6, cap = capture { content = "wy", start = 21, end = 23 } });
+	if (ts[0].cap.end == 777) { return 66; };
+	if (ts[0].cap.end != 13) { return 1; };
+	if (ts[0].cap.start != 11) { return 2; };
+	if (ts[1].cap.end != 23) { return 3; };
+	if (ts[1].cap.content.len != 2) { return 4; };
+	if (ts[1].pc != 6) { return 5; };
+	return 59;
+};