lib/strings-core tests: hand-main plumbing -> assert (@test conversion B4)

bytes EXCLUDED: its green masked a real signalled corruption (filed;
conversion rides the fix). stringstest documents the per-row signalled
pinpoint loss.

lib/fnmatch/fnmatchtest.ww

@@ -8,33 +8,19 @@
 // byte-wise and those would match byte-identically but obscure the
 // ASCII semantics the test is asserting.
 //
-// Failure path: each @test fn bumps `signalled` to its slot index,
-// `check` does `exit(signalled + 10)` on miscompare so the harness
-// reports `WEXITSTATUS = 11..N` pointing at the failing scenario.
-// Same convention as lib/log/logtest.
+// Failure path: a miscompare aborts via the assert/abort builtin
+// (task #5 @test conversion).
 
 package fnmatch_test;
 
 import fnmatch;
 
-// Direct rt_syscall binding rather than `use os;` — os exports
-// read/write/close, which collide with io.read/write/close under the
-// driver's flat-scope concat. Mirrors logtest / fmttest / bufiotest.
-@symbol("rt_syscall") fn syscall1ww(num: i64, a: i64) i64;
-fn doexit(code: i32) void = {
-	syscall1ww(60i64, code: i64);
-};
-
-let signalled: i32 = 0;
-
-fn fail() void = { doexit(signalled + 10); };
-
 // check — pin one row. `flags` is taken as i32 and cast to
 // fnmatch.flag so the test rows can read as integer bitmasks
 // without dragging enum literals into every line.
 fn check(pat: str, s: str, expected: bool, flags: i32) void = {
 	let f: fnmatch.flag = flags as fnmatch.flag;
-	if (fnmatch.fnmatch(pat, s, f) != expected) { fail(); };
+	assert(!(fnmatch.fnmatch(pat, s, f) != expected));
 };
 
 // ---- basic literal / wildcard cases ---------------------------------
@@ -263,13 +249,13 @@ fn check(pat: str, s: str, expected: bool, flags: i32) void = {
 };
 
 export fn main() i32 = {
-	signalled = 1; basic();
-	signalled = 2; brackets();
-	signalled = 3; ctype();
-	signalled = 4; period();
-	signalled = 5; noescape();
-	signalled = 6; musl_basic();
-	signalled = 7; pathname();
-	signalled = 8; combined();
+	basic();
+	brackets();
+	ctype();
+	period();
+	noescape();
+	musl_basic();
+	pathname();
+	combined();
 	return 0;
 };