security: fix 6 critical vulnerabilities across chatbot and backend

feat: add pagination to HotelListPage, fix i18n in hotel cards, strengthen chatbot guardrails

feat(chatbot): thread user_memory through LLM pipeline — context builder, inference, openai generator

feat(chatbot): add chain-of-thought logic for personalize_recommend intent

Round 12: Quality improvements + Chatbot enhancements

feat(chatbot): expand KB to 9474 destinations & upgrade all components (v4.0.0)

Revert "feat: upgrade LLM layer v3.2 - multi-provider, caching, conversation memory, safety"

feat: upgrade LLM layer v3.2 - multi-provider, caching, conversation memory, safety

fix(chatbot): resolve 7 critical issues - KB expansion, pipeline fixes, dynamic responses