## Summary
This lets skill loading split `permissions.network` into two distinct
pieces:
- `permissions.network.enabled` still feeds the skill
`PermissionProfile` and remains the coarse gate for whether the skill
can use network access at all.
- `permissions.network.allowed_domains` and
`permissions.network.denied_domains` are lifted into a new
`SkillManagedNetworkOverride` so managed-network sessions can start
per-skill scoped proxies with the right domain overrides.
The change also updates `SkillMetadata` construction sites and adds
loader tests covering YAML parsing plus normalization of the network
gate vs. domain override fields.
## Follow-up
A PR that uses the network_override to spin up a skill-specific proxy if
network_override is not none.