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.

gpu-rent.vars.example

@@ -15,6 +15,11 @@
 # SCAN_POOLS=ru-6,ru-7
 # FLAVOR_PREFERENCE=4090-24,4090-48,a5000,a100-40
 # SWARMUI_LOCAL_PORT=17801
+# DATA_VOLUME_SIZE_GB=100
+# DEFAULT_FLAVOR_ID=
+# DEFAULT_SPOT=true
+# ENABLE_SWARMUI=true
+# WORKLOAD=llm          # то же что ENABLE_SWARMUI=false (только LLM)
 # LLM_RUNTIME=none
 # OLLAMA_LOCAL_PORT=17811
 # LLAMACPP_LOCAL_PORT=17812