Enhance LLM and SwarmUI integration with improved configuration options

- Updated `env.example` and `gpu-rent.vars.example` to include new variables for LLM runtime and SwarmUI options.
- Refactored CLI commands to support interactive selection of LLM runtime and workload type (SwarmUI, LLM, or both).
- Improved access link generation to handle cases where SwarmUI is disabled, providing clearer user feedback.
- Enhanced provisioning logic to conditionally bootstrap SwarmUI based on user configuration, allowing for LLM-only setups.
- Updated documentation across multiple files to reflect changes in LLM integration, CLI usage, and configuration management.

docs/spike-notes.md

@@ -103,12 +103,13 @@
 
 ```powershell
 .\gpu-rent.ps1 up --yes --ollama
+# или интерактивно: up → меню runtime/пресет
 ```
 
 | Шаг | OK? |
 | --- | --- |
-| Ollama на :17811 через туннель | |
-| `ollama pull` из манифеста | |
+| Ollama :17811 или llama.cpp :17812 через туннель | |
+| pull / GGUF из манифеста | |
 | `LLM_RUNTIME=none` гасит unit на следующем up | |
 
 См. [llm.md](llm.md).