feat(create): scaffold repositories via templates with preview and mirror setup

https://chatgpt.com/share/693f5bdb-1780-800f-a772-0ecf399627fc

tests/e2e/test_repos_create_preview_output.py

@@ -0,0 +1,42 @@
+from __future__ import annotations
+
+import io
+import unittest
+from contextlib import redirect_stdout
+from unittest.mock import patch
+
+from pkgmgr.actions.repository.create import create_repo
+
+
+class TestE2ECreateRepoPreviewOutput(unittest.TestCase):
+    def test_create_repo_preview_prints_expected_steps(self) -> None:
+        cfg = {"directories": {"repositories": "/tmp/Repositories"}, "repositories": []}
+
+        out = io.StringIO()
+        with (
+            redirect_stdout(out),
+            patch("pkgmgr.actions.repository.create.os.path.exists", return_value=False),
+            patch("pkgmgr.actions.repository.create.generate_alias", return_value="repo"),
+            patch("pkgmgr.actions.repository.create.save_user_config"),
+            patch("pkgmgr.actions.repository.create.os.makedirs"),
+            patch("pkgmgr.actions.repository.create.render_default_templates"),
+            patch("pkgmgr.actions.repository.create.write_mirrors_file"),
+            patch("pkgmgr.actions.repository.create.setup_mirrors"),
+            patch("pkgmgr.actions.repository.create.subprocess.run"),
+        ):
+            create_repo(
+                "github.com/acme/repo",
+                cfg,
+                "/tmp/user.yml",
+                "/tmp/bin",
+                remote=False,
+                preview=True,
+            )
+
+        s = out.getvalue()
+        self.assertIn("[Preview] Would save user config:", s)
+        self.assertIn("[Preview] Would ensure directory exists:", s)
+
+
+if __name__ == "__main__":
+    unittest.main()