Function resolve_pinned 

pub fn resolve_pinned(
    candidates: &[ResolveCandidate<'_>],
    pin: &str,
    model_type: &str,
    hidden_size: usize,
) -> Result<usize, TargetResolveError>

Resolve a --kernel-target pin: the named target wins unconditionally over the tie-break, but must exist and must declare the checkpoint’s (model_type, hidden_size) (exact or wildcard).