refactor(reasoning)!: remove Node-RED engine and integrations

BREAKING CHANGE: NODE_RED reasoning is no longer supported. Unsupported
mode values fall back to PROXY. PROXY and OPENAI remain available.

AGENTS.md

@@ -3,7 +3,7 @@
 ## Scope and working conventions
 
 This repository is Vocero: a browser voice client, its FastAPI integration
-server, a speech pipeline, and optional Node-RED flows. Use the code, commands,
+server, and a speech pipeline. Use the code, commands,
 configuration, and documentation within this checkout. Do not assume other
 repositories or developer-specific directories are available.
 
@@ -48,7 +48,6 @@ root. HTTP routes mentioned below are URLs, not filesystem paths.
 | `s2s-client/s2s_client/realtime/`  | WebSocket relay, event handling, marker filtering, and audio forwarding                     |
 | `s2s-frontend/`                    | React, TypeScript, Tailwind, and Vite browser application                                   |
 | `speech_to_speech/`                | Separately run VAD → STT → LLM → TTS pipeline and realtime API                              |
-| `s2s-reasoning-engine/`            | Optional Node-RED reasoning/logging service                                                 |
 | `start_ui.sh`                      | Dependency sync and supervision of FastAPI plus Vite                                        |
 | `docs/`                            | Maintained technical documentation, examples, and historical proposals                      |
 
@@ -201,12 +200,11 @@ sync; a separate sync is optional to prepare dependencies before restarting.
 Ensure the required uv and Node/npm are on that process's PATH. Verify the live
 PM2 script path and environment before making claims about a deployment.
 
-The launcher does not start or restart `speech_to_speech/` or Node-RED. A configured
+The launcher does not start or restart `speech_to_speech/`. A configured
 speech URL does not prove which source revision or implementation runs there.
 `SPEECH_TO_SPEECH_URL` pins a direct browser connection; `S2S_PROXY_TARGET` enables
-the local relay. Either disables load-balancer mode. The Node-RED flows in
-`s2s-reasoning-engine/flows.json` are log-only; preserve the meaning of `log_only`
-responses.
+the local relay. Either disables load-balancer mode. Reasoning supports `PROXY`
+and `OPENAI`; unknown `S2S_REASONING_TYPE` values fall back to `PROXY`.
 
 The backend Docker image serves APIs, WebSockets, and root `docs/`, not the React
 UI. Build with the repository root as context and `s2s-client/Dockerfile`; the