fix: disable cloudflare AI gateway and update model IDs

fix: resolve DB race condition and add SambaNova/HuggingFace free LLM providers

fix(backend): update cerebras model name to llama3.3-70b to resolve 404 errors

feat: Migrate email from Gmail SMTP to Resend HTTP API

Rebrand to PolicyEye, add CONTRIBUTING.md, deployment prep for HF Spaces + Vercel

fix: per-user policy isolation, cross-user cache clone, improved JWT auth resilience

fix: resolve config import error in core.security

refactor: project structure cleanup and core packaging