[Build] Add Gemini integration for natural conversation

## GitHub Update **Repository:** [MKWcorp/CINTAI](https://github.com/MKWcorp/CINTAI) **Author:** MKWcorp **Date:** 11/8/2025, 5:24:14 PM **Commit:** [`1906600`](https://github.com/MKWcorp/CINTAI/commit/190660090905bde88da33fe60a41b06f231b1d8c) ### Commit Message Add Gemini integration for natural conversation - Create lib/gemini.ts with Gemini 2.0 Flash integration - Add natural conversation support for non-action messages - Update GetCirclo webhook to use Gemini for general chat - Add GEMINI_API_KEY to environment variables - Add @google/generative-ai dependency - Gemini responds to skincare questions naturally - Fallback to default greeting if Gemini unavailable --- _This story was imported from historical commits._