♻️ refactor(skills): rename repo skills source dir

move the repository skills source from `codex/skills` to `skills`.

update vendor/install_skills paths, thirdparty sync pipeline, docs, and regression tests, including deployment-route e2e coverage.

tests/test_tsl_entrypoints_consistency.py

@@ -7,7 +7,8 @@ README = ROOT / "README.md"
 PLAYBOOK_EXAMPLE = ROOT / "playbook.toml.example"
 SKILLS_DOC = ROOT / "SKILLS.md"
 TEMPLATES_CI_README = ROOT / "templates" / "ci" / "README.md"
-REMOVED_TSL_GUIDE = ROOT / "codex" / "skills" / "tsl-guide"
+TEMPLATES_README = ROOT / "templates" / "README.md"
+REMOVED_TSL_GUIDE = ROOT / "skills" / "tsl-guide"
 
 class TslEntrypointsConsistencyTests(unittest.TestCase):
     def test_ruleset_lists_canonical_tsl_layers(self):
@@ -44,6 +45,19 @@ class TslEntrypointsConsistencyTests(unittest.TestCase):
         self.assertNotIn("vendoring", SKILLS_DOC.read_text(encoding="utf-8"))
         self.assertNotIn("vendoring", TEMPLATES_CI_README.read_text(encoding="utf-8"))
 
+    def test_repo_docs_use_platform_neutral_skills_source_dir(self):
+        readme_text = README.read_text(encoding="utf-8")
+        skills_text = SKILLS_DOC.read_text(encoding="utf-8")
+        templates_text = TEMPLATES_README.read_text(encoding="utf-8")
+
+        self.assertIn("`skills/`", readme_text)
+        self.assertIn("`skills/`", skills_text)
+        self.assertIn("├── skills/", templates_text)
+
+        self.assertNotIn("`codex/skills/`", readme_text)
+        self.assertNotIn("`codex/skills/`", skills_text)
+        self.assertNotIn("├── codex/skills/", templates_text)
+
     def test_repo_no_longer_ships_tsl_guide_skill(self):
         self.assertFalse(REMOVED_TSL_GUIDE.exists())
         self.assertNotIn("tsl-guide", README.read_text(encoding="utf-8"))