Function grant 

pub fn grant(manifest: &PluginManifest, tier: TrustTier) -> GrantOutcome

Compute the effective grant for manifest under tier.

The only tier-dependent filter in v1 is proc:spawn (bundled-only); every other requested capability is granted as declared. User-consent narrowing (a user-installed plugin’s grant reduced to what the user approved) plugs in here in a later slice — the GrantOutcome::denied channel already carries the “requested but withheld” set that a consent step would populate.