feat: support registry collections and docker publishing

tests/test_custom_sources.py

@@ -137,6 +137,35 @@ class CustomSourceTests(unittest.TestCase):
         self.assertIn("owned/code-review", result.stderr)
         self.assertIn("company/code-review", result.stderr)
 
+    def test_custom_source_namespace_is_not_shadowed_by_registry_collection(self) -> None:
+        company = self.home / "company"
+        expected = write_skill(company / "skills", "code-review")
+        registry_repo = self.home / "registry-repo"
+        write_skill(registry_repo / "skills", "other-skill")
+        self.skills_home.joinpath("registry.yaml").write_text(
+            "company:\n"
+            f"  repo: {registry_repo}\n"
+            "  ref: main\n"
+            "  path: skills\n",
+            encoding="utf-8",
+        )
+        added = self.run_skiff("source", "add", "company", "--local", str(company))
+
+        result = self.run_skiff(
+            "add",
+            "company/code-review",
+            "-g",
+            "-a",
+            "codex",
+        )
+
+        self.assertEqual(added.returncode, 0, added.stderr)
+        self.assertEqual(result.returncode, 0, result.stderr)
+        self.assertEqual(
+            (self.home / ".codex" / "skills" / "code-review").resolve(),
+            expected.resolve(),
+        )
+
     def test_sync_uses_manifest_source(self) -> None:
         company = self.home / "company"
         expected = write_skill(company / "skills", "code-review")