Move proxy_pass directive to correct position in nginx location block and
update proxy settings: enable request body forwarding (proxy_pass_request_body
on) and pass original Content-Length header (from $content_length variable)
instead of stripping it, ensuring auth-proxy receives full request payloads.
- Migrate IP-based temporary whitelisting from file to SQLite storage
- Add REST API endpoints for managing temporary and permanent whitelists
- Create `.env.example` with required environment variables
- Document API endpoints in README.md and docs/api.md
- Add new dependency `modernc.org/sqlite` for SQLite support
- Update deployment and security documentation
