Remove MetaBot coupling from uninstall and workspace init.

Keep silent cleanup of legacy metabot stubs; drop METABOT_HOME symlink.

tests/test_uninstall.py

@@ -53,6 +53,7 @@ class TestUninstall:
         assert not (local_bin / "completions").exists()  # empty dir cleaned
         assert not (fake_home / "Desktop" / "Xiaohe Agent.app").exists()
         assert (fake_home / ".xiaohe" / "agent" / "config.json").is_file()
+        # Legacy leftover dir kept unless --all
         assert (fake_home / ".metabot" / "bots.json").is_file()
         assert (fake_home / ".mytoolkit" / "config.json").is_file()
         assert (fake_home / "workspace").is_dir()
@@ -64,7 +65,7 @@ class TestUninstall:
         )
         assert result.exit_code == 0
         assert not (fake_home / ".xiaohe").exists()
-        assert not (fake_home / ".metabot").exists()
+        assert not (fake_home / ".metabot").exists()  # legacy leftover
         assert not (fake_home / ".mytoolkit").exists()
         assert (fake_home / "workspace").is_dir()  # workspace never touched