* feat(sandbox): add network_via_proxy_only and allow_direct_dns policy fields
Config surface for network lockdown: network_via_proxy_only confines a
sandboxed package manager's outbound network to the PMG proxy;
allow_direct_dns is its escape hatch re-opening direct DNS. Both follow
the existing pointer-bool inheritance pattern in MergeWithParent. Lint
warns when allow_direct_dns is set without network_via_proxy_only, where
it has no effect.
The fields are declared and inherited but unread; enforcement lands with
the ExecutionContext plumbing and Seatbelt lockdown translation.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PqMU5GNBbQvQct9nxek1VS
* fix(sandbox): deep-copy new pointer flags in profile resolution
expandPolicyPaths re-points the older pointer booleans so callers cannot
corrupt the registry-cached policy; the new NetworkViaProxyOnly and
AllowDirectDNS fields need the same isolation.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PqMU5GNBbQvQct9nxek1VS
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Co-authored-by: Claude <noreply@anthropic.com>
