AI Chatbot Web App with Spring Boot, Streaming Chat and Multi-LLM Routing

I want a production-ready AI chatbot that works as a personal assistant, streaming each token to the browser in real time. The core must be a clean Spring Boot REST backend that exposes an SSE endpoint, backed by PostgreSQL so every conversation—including its topic-based context—survives restarts... (Budget: $30 - $250 USD, Jobs: AI Automation, AI Chatbot, AI Chatbot Development, AI Model Integration, Java, JavaScript, PHP, PostgreSQL, Spring Boot, Vue.js)