Fix summaries table schema

Switch to gemini-3-flash-preview model

Update Gemini API key

Fix: Use raw_text column instead of content

Fix: Use Gemini REST API instead of SDK

Fix T5 model paths for proper loading

Fix T5 model paths for proper loading

Add T5 model integration for real summary generation

Fix summaries API: use correct table schema from supa.sql

Add APIs for local T5 model: content retrieval and summary submission

Backend FastAPI with FAISS for Hugging Face Spaces