Add configurable UI settings (colors, font, avatar) to config and admin panel

Add configurable chatbot texts (disclaimer, welcome message) via config/chatbot_settings.json

Prune interview features, fix production issues: rate limiting, missing deps, XSS, LLM reuse, empty-context guardrail

Add retrieval optimization: HyDE, cross-encoder reranking, RAGAS evaluation

add session isolation

optimize efficiency

add multi query

retrieve more file

initial deploy