test(integration): move create repo preview test from e2e and mock git commands

- Reclassify create repo preview test as integration test
- Rename test class to drop E2E naming
- Replace subprocess mock with core.git command mocks (init/add_all/commit)
- Patch get_config_value to avoid git config dependency

https://chatgpt.com/share/694150de-873c-800f-a01d-df3cc7ce25df

tests/e2e/test_repos_create_preview_output.py

@@ -1,42 +0,0 @@
-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()