Update extensions and documentation for LLM integration and CLI enhancements

- Added support for a new extension, `swarm-assistent`, in `extensions.example.yaml` with a requirement for `ollama`.
- Enhanced the README.md to clarify the setup process and provide a quick start guide for using extensions.
- Updated documentation in `llm.md` to reflect the opt-in nature of LLM support and provide clearer instructions for enabling it.
- Improved the `autocomplete.md` to detail the automatic setup of word lists during the initial launch.
- Revised `cli.md` to include new commands and options related to LLM runtime handling and extension management.
- Enhanced the `spike-notes.md` to guide users through the first live run with a focus on LLM integration.

extensions.example.yaml

@@ -2,8 +2,14 @@
 # Empty/missing file → no extra extensions, stock SwarmUI.
 # swarmui = C# repos cloned to src/Extensions
 # comfy   = Python custom nodes cloned to ComfyUI DLNodes
+# requires: none (default) | ollama | llamacpp | any-llm
+#   — clone only when LLM_RUNTIME matches (ollama / llamacpp / either)
 
-swarmui: []
+swarmui:
+  - url: https://gitea.hsrv.site/mrleo1nid/swarm-assistent.git
+    ref: main
+    dir: swarm-assistent
+    requires: ollama
   # - url: https://github.com/org/SwarmUI-MyExt.git
   #   ref: main
   #   dir: MyExt