Hyperlight blockedHosts overrides defaultPolicy=block #786

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Relevant area(s)

Windows

Brief description of your issue

The Hyperlight backend treats a non-empty network.blockedHosts list as an allow-by-default blocklist even when network.defaultPolicy remains at its secure default of block. This silently widens the requested network boundary and contradicts the meaning of defaultPolicy=block.

Steps to reproduce

1. Run a Hyperlight sandbox with network.defaultPolicy omitted or set to block.
2. Add one entry to network.blockedHosts.
3. Attempt network access to a destination not in blockedHosts.

Expected behavior

network.defaultPolicy=block remains authoritative. blockedHosts must not enable networking to every unlisted destination; the backend should either preserve block-by-default semantics or reject the incompatible policy combination.

Actual behavior

network_policy_from_request selects Hyperlight's BlockList whenever blockedHosts is non-empty, before checking defaultPolicy. The resulting policy allows all destinations except the listed hosts. The generic boundary-relaxation audit also omits blockedHosts, so this backend-specific relaxation is not logged.