test(host-conformance): delete a named section in the C3 broken-link case

The case removed the first .md readdirSync returned under gstack-qa/sections.
qa-patterns.md and system-functional.md are referenced only in table form, which
setup --status does not count as section links, so on an ext4 directory order
that listed one of them first the deleted file broke nothing and --status exited
0: deterministic red on remote-gate VMs, green on Actions. Delete scope.md, which
every host's rendered SKILL.md reads.

Closes #3479

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

test/host-conformance.test.ts

@@ -202,8 +202,7 @@ describe.skipIf(process.platform === 'win32')('host conformance kit', () => {
     const router = join(f.home, '.codex/skills/gstack/SKILL.md');
     rmSync(router);
     symlinkSync(join(src, '.agents/skills/gstack/SKILL.md'), router);
-    const qa = join(src, '.agents/skills/gstack-qa/sections');
-    rmSync(join(qa, readdirSync(qa).find(n => n.endsWith('.md'))!));
+    rmSync(join(src, '.agents/skills/gstack-qa/sections/scope.md'));
     const status = runSetup(f, join(src, 'setup'), ['--status']);
     // A1: broken section links make --status exit 1 instead of always 0.
     expect(status.status).toBe(1);