Enhance bootstrap script for .NET installation and error handling

- Added `wget` to the package installation list for improved script functionality.
- Implemented a fallback mechanism using `curl` for .NET installation if the primary script fails, enhancing robustness.
- Updated ownership change for the installation directory to ensure proper permissions for the user.
- Enhanced logging for error scenarios during .NET installation, providing clearer feedback for troubleshooting.
- Added tests to verify the new fallback functionality and ownership changes in the bootstrap script.

tests/test_bootstrap.py

@@ -19,3 +19,7 @@ def test_bootstrap_script_is_native_swarmui():
     assert "light bootstrap — пропускаем apt-get" in script
     # llm-only re-up can skip apt when data marker exists (not only Swarm boot marker)
     assert 'MARKER_DATA' in script or ".gpu-rent-ready" in script
+    # .NET: chown before Swarm install script; curl fallback if wget/perms fail
+    assert "install_dotnet_via_curl" in script
+    assert "chown -R" in script
+    assert "wget" in script