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.

s2s-client/CHANGELOG.md

@@ -9,6 +9,9 @@ the implementation at the recorded date; current operating instructions live in
 
 ### Changed
 
+- Removed the optional workflow reasoning service, its configuration, transcript
+  forwarding, and browser integration. Reasoning supports `PROXY` and `OPENAI`;
+  unsupported mode values fall back to `PROXY`.
 - Filter the specific Starlette TestClient / AnyIO `BlockingPortal` deprecation
   in pytest while retaining the runtime versions used for compatibility captures.
 - Added a uv-managed Python 3.12 environment and Ruff, mypy, and pytest quality
@@ -33,8 +36,6 @@ the implementation at the recorded date; current operating instructions live in
 - Translated developer comments, diagnostics, internal model instructions, and
   local identifiers into English. Sanitization accepts both the former Spanish
   and new English internal tool-result wrappers.
-- Renamed the reasoning engine's log-only acknowledgment field to `received`
-  and its debug phase to `log_only_phase1`.
 - Standardized browser labels, accessibility text, account/profile dialogs,
   session feedback, and built-in API errors in Spanish. The interface declares
   `lang="es"`; internal instructions and diagnostics remain English.