#66 API: Manage IP Whitelist

Implement endpoints to manage IP whitelist for tenant. Endpoints: - GET /api/v1/security/ip-whitelist - List whitelisted IPs - POST /api/v1/security/ip-whitelist - Add IP/CIDR range - DELETE /api/v1/security/ip-whitelist/{id} - Remove IP/CIDR Request Body (POST): - ip_or_cidr: string (required) - description: string (optional) - expires_at: datetime (optional) Required Permissions: tenant_admin or system_admin Implementation Requirements: - Support both individual IPs and CIDR ranges - Validate IP format - Prevent locking out current admin - Warning if whitelist will block current IP - Support IPv4 and IPv6 - Temporary whitelist entries with expiration With ultra attention to details and correctness. Before closing: write comment summarizing implementation with screenshot.