Document current coding-workflow stack state

Snapshot of where opencode + Qwen3-Coder + MCPs + Kimi-Linear + voice
  + Phoenix tracing land today, plus in-flight (oc-tree, kimi-linear
  context ramp) and next (ComfyUI) items with pointers to per-project
  NEXT_STEPS.md guides.

pyinfra/framework/compose/openwebui.yml

@@ -17,6 +17,11 @@ services:
       - "host.docker.internal:host-gateway"
     environment:
       - OLLAMA_BASE_URL=http://host.docker.internal:11434
+      # vLLM (Kimi-Linear) exposed as an OpenAI-compatible backend. The
+      # model isn't strongly tool-trained — opencode's agentic system
+      # prompt confuses it. OpenWebUI's plain chat UI is the right home.
+      - OPENAI_API_BASE_URLS=http://host.docker.internal:8000/v1
+      - OPENAI_API_KEYS=dummy
       # Built-in web search via the project's SearXNG instance.
       - ENABLE_RAG_WEB_SEARCH=true
       - RAG_WEB_SEARCH_ENGINE=searxng