Show clear guidance when provider has no key configured instead of cryptic 401. Add friendly messages for 429/403 errors during streaming. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
FastAPI backend (wiki-vector-chat.py) with Odysseus-style frontend. Features: multi-provider LLM, Wiki KB + VectorDB RAG, session history, chat modes, save-to-wiki, markdown rendering, SSE streaming. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>