test(codex): align install contracts with no gsd skill copies

tests/install-minimal-all-runtimes.test.cjs

@@ -179,6 +179,12 @@ function expectedSkillSet() {
   return new Set([...MINIMAL_SKILL_ALLOWLIST]);
 }
 
+function expectedManifestSkillSet(runtime) {
+  // Codex no longer materializes gsd-* skill files in minimal mode.
+  if (runtime === 'codex') return new Set();
+  return expectedSkillSet();
+}
+
 describe('install: --minimal honoured for every runtime in --global mode', () => {
   for (const runtime of SKILL_RUNTIMES) {
     test(`${runtime} --global --minimal emits exactly the core skill set, zero agents`, () => {
@@ -193,7 +199,7 @@ describe('install: --minimal honoured for every runtime in --global mode', () =>
           `${runtime} global manifest.mode should be "minimal"`);
         assert.deepStrictEqual(
           [...manifestSkillSet(manifest)].sort(),
-          [...expectedSkillSet()].sort(),
+          [...expectedManifestSkillSet(runtime)].sort(),
           `${runtime} global should record exactly the MINIMAL allowlist in the manifest`,
         );
         assert.strictEqual(manifestAgentCount(manifest), 0,
@@ -219,7 +225,7 @@ describe('install: --minimal honoured for every runtime in --local mode', () =>
           `${runtime} local manifest.mode should be "minimal"`);
         assert.deepStrictEqual(
           [...manifestSkillSet(manifest)].sort(),
-          [...expectedSkillSet()].sort(),
+          [...expectedManifestSkillSet(runtime)].sort(),
           `${runtime} local should record exactly the MINIMAL allowlist in the manifest (regression guard for #2923)`,
         );
         assert.strictEqual(manifestAgentCount(manifest), 0,

tests/installer-migration-install-integration.test.cjs

@@ -174,6 +174,14 @@ function assertHasGsdDirectory(root, relPath) {
   );
 }
 
+function assertNoGsdDirectoryEntries(root, relPath) {
+  assert.equal(
+    listDirNames(root, relPath).some((name) => name.startsWith('gsd-')),
+    false,
+    `${relPath} should not contain generated GSD entries`
+  );
+}
+
 function assertFreshInstallContract(runtime, targetDir) {
   const contract = RUNTIME_INSTALL_CONTRACTS[runtime];
   assert.ok(contract, `missing runtime install contract for ${runtime}`);
@@ -201,7 +209,11 @@ function assertFreshInstallContract(runtime, targetDir) {
   );
 
   if (contract.surface === 'flat-skills') {
-    assertHasGsdDirectory(targetDir, 'skills');
+    if (runtime === 'codex') {
+      assertNoGsdDirectoryEntries(targetDir, 'skills');
+    } else {
+      assertHasGsdDirectory(targetDir, 'skills');
+    }
   } else if (contract.surface === 'hermes-skills') {
     assertHasGsdDirectory(targetDir, path.join('skills', 'gsd'));
     assert.ok(