Add comprehensive tests for isPrivateIP() and getUserIP() functions. These tests currently fail as the functions are not yet implemented. Tests cover: - isPrivateIP: loopback, private ranges (10/172/192), AWS metadata, public IPs - getUserIP: REMOTE_ADDR fallback, X-Forwarded-For parsing and trimming Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>