* feat(sandbox): allow egress to private IP space via allowed_ips policy field
Add an allowed_ips field to NetworkEndpoint that accepts CIDR notation and
exact IPs, enabling sandboxes to reach private IP space under policy control
while maintaining SSRF protections for loopback and link-local addresses.
Three modes are supported:
- Default (no allowed_ips): all private IPs blocked (existing behavior)
- Host + allowlist: domain must resolve to an IP in allowed_ips
- Hostless allowlist (no host): any domain allowed if resolved IP matches
Co-authored-by: John Myers <johntmyers@users.noreply.github.com>
Drew Newberry