SOS (urge.tsx) uses /api/coach/message as a stateless LLM proxy for game
comments, share drafts and the stream fallback — sending SOS_BOOT +
[INTERN:] prompts. The endpoint persisted the full messages array into
coachSession for pro/legend users, so those internal prompts and the raw
JSON replies leaked into the Coach chat history as visible bubbles.
- Reactivate the sosMode flag (already sent by all three SOS call-sites):
when set, the endpoint skips coachSession persistence, memory extraction
and feedback detection — pure LLM proxy, no shared state.
- Add a defensive filter on /api/coach/history that strips internal
messages (SOS_BOOT, [INTERN:], [SYSTEM-HINT], raw JSON / [[CHIPS]]
replies) so already-contaminated sessions self-heal on next load.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
