## Why
Linux proxy-routed sandboxing denied standalone Unix sockets even when the effective network policy enabled `dangerously_allow_all_unix_sockets`.
## What changed
- Carry Unix socket permissions in `ManagedNetworkSandboxContext` and pass the prepared context through Linux sandbox launches with `--managed-network`.
- Allow `AF_UNIX` socket creation in proxy-routed mode when `dangerously_allow_all_unix_sockets` is enabled, while preserving network namespace isolation and restrictions on other socket families.
- Keep standalone Unix sockets denied by default and for path-only grants. Default missing fields in older serialized contexts to restrictive values.
## Testing
Add coverage for policy preparation and transport, legacy deserialization, and malformed policy rejection. Add a Linux integration test covering default denial, path-only denial, and explicit allow-all access, while checking that direct TCP access and `AF_NETLINK`/`AF_VSOCK` sockets remain blocked.
GitOrigin-RevId: 2695b945ad3e59fcb3faf7662d852a26650af16c
## Why
Sandboxes that enforce endpoint access directly need dedicated loopback proxy ports instead of shared SID-attributed ingress.
## What changed
Expose `ManagedProxyRouting` through `NetworkProxyBuilder::managed_proxy_routing`. Selecting `DedicatedListeners` reserves per-proxy loopback listeners on Windows as well as other platforms. Keep `SharedIngress` as the default and include the routing mode in proxy equality.
## Testing
Add regression coverage for distinct loopback endpoints, sandbox port metadata, and HTTP and SOCKS allow/deny policy enforcement. On Windows, verify that dedicated routing requires no restricting SID and omits the shared-ingress proxy-port environment variable.
GitOrigin-RevId: e198891bef1d089f9492d2982505a2d6bb002a74
viyatb-oai