Enhance SwarmUI integration and GPU environment verification

- Updated CLI documentation to reflect the new handling of `CIVITAI_API_TOKEN`, which is now automatically passed to SwarmUI user settings during startup.
- Improved the `render_access_panel` function to include additional warnings for idle-killer failures and stack errors, enhancing user feedback.
- Introduced a new function `seed_swarmui_api_keys` to manage API key injection into SwarmUI, ensuring seamless integration with the Model Downloader.
- Enhanced GPU environment verification logic to include fail-fast checks for critical components like CUDA, improving error handling and user notifications.
- Updated tests to validate the new API key handling and access panel behavior, ensuring robustness in the integration process.

tests/test_bootstrap.py

@@ -14,5 +14,8 @@ def test_bootstrap_script_is_native_swarmui():
     assert "Data/Autocompletions" in script
     assert "mkfs.ext4" in script
     assert "apt-get upgrade" not in script
-    assert ".gpu-rent-ready" in script
-    assert "src/BuiltinExtensions/ComfyUIBackend/DLNodes" in script
+    assert "GPU_RENT_BOOTSTRAP_LIGHT" in script
+    assert "GPU_RENT_SKIP_SWARMUI" in script
+    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