Fix session isolation: scope all queries to session_id

Fix citation links and PDF viewer for HF Spaces via APP_PUBLIC_URL env var

Poll upload status and show indexed chunk count instead of raw paper ID

Add conversation history to chat — last 3 exchanges sent to LLM

Fix upload dir paths, nginx body size limit, arXiv fetch timeout

Add HuggingFace Spaces deployment + session isolation

Fixed Citation PDF Viewer functionality

Fixed Document Viewer

Initial commit: Academic Research RAG project