[KM-490 & KM-491][EMA][FE Demo] Migrate helper prompt to v2 API with data driven

fix: route API calls through server-side proxy to fix undefined backend URL

feat: improve UI components and chatbot configuration

update api.ts fixing incorrect backend url pointing

Refactor API calls to direct backend integration, add chatbot configuration system, and improve UI components

[KM-422] [EMA][FE] Interface prototype for External Demo