fix: downgrade next.js to v15 to resolve dependency conflict

Correctly implement Portal in KnowledgeGraphModal and fix imports

Fix Knowledge Graph modal z-index and mobile responsiveness

Fix RAGChat syntax errors and polish UI

fix: resolve Mongoose CastErrors by renaming 'type' field and restoring models

fix: Mongoose validation errors and enforce ultra-concise AI responses

feat: Improve AI responses and session-scoped graph storage

fix: Resolve nested button hydration error in SessionSidebar

feat: Multi-session chat with persistent storage

feat: Implement comprehensive security measures

feat: Add comprehensive README and remove branding

feat: MongoDB file storage + Neo4j cloud integration

feat: Enhanced CSV parsing, markdown chat, and optimized RAG

feat: Unified RAG Management System with Gemini 1.5

Initial commit