Function classify_with 

pub fn classify_with(
    registry: &TypeRegistry,
    path: &Path,
    prefix: Option<&[u8]>,
) -> Classification

Classify against a specific registry, with an optional bounded content prefix.

Known exact-name and ordinary extension matches avoid deep detection. The .h ambiguity and generated-file flag alone inspect their documented bounded prefix. Callers may pass a larger buffer; all content-dependent helpers enforce smaller internal limits.