## Why
Seatbelt ignored Unix socket permissions in `ManagedNetworkSandboxContext`, which could omit allowed sockets or inherit a live proxy's broader permissions.
## What changed
Use the prepared context's `allow_unix_sockets` and `dangerously_allow_all_unix_sockets` settings when present, falling back to the live proxy only when no prepared context exists. Normalize allowlisted paths and preserve explicit extra socket allowances.
## Testing
Add regression coverage for prepared-policy precedence, empty allowlists, invalid relative paths, and explicit extra allowances. Extend macOS exec-server tests to cover prepared and executor-local proxy socket permissions, including explicit allow-all behavior without unrestricted network access.
GitOrigin-RevId: 3372e1f2f1b161e60bde585db8d70b4e3a0b1854
c18db9ba69