Function diskann_feature_status 

pub fn diskann_feature_status(
    configured_kind: VectorBackendKind,
    feature_compiled: bool,
    strict: bool,
) -> DiskAnnFeatureStatus

Decide what should happen when configured_kind is booted in a build where feature_compiled tells whether the diskann cargo feature is present, honoring the vector.strict config knob.

Pure and side-effect free by design — Kernel::boot calls this with cfg!(feature = "diskann") and turns the result into a crate::console::BootEvent or a KernelError::Boot; keeping the decision itself free of kernel/boot types makes it testable without booting a kernel.