feat: production-ready submission - hackathon-winning notebook, timeline blog, 14 bug fixes, reward plots

Fix: Run both FastAPI and Next.js servers, add proxy routes for /reset and /step

feat: Finalized OpenEnv CVE Triage Backend integration and completed Hackathon README requirements

fix: add gemini-1.5-flash-8b and 1.0-pro to fallback chain

fix: gemini fallback handlers and input paste

fix: Use valid Gemini model names in fallback chain

fix: Add Gemini retry logic with model fallback chain (2.5→2.0→1.5) to handle 429 rate limits

feat: Nexus Intelligence Platform - SAST + DAST unified scanner