Function response_header_allowed 

pub fn response_header_allowed(name: &str, value: &str) -> bool

Whether a handler-supplied response header may pass to the wire — THE ONE law both execution tiers (the interpreter bridge and AOT-emitted code) apply before merging a LOGOS Response.headers map, so they can never drift: the name must be non-empty, must not be writer-owned framing or hop-by-hop (connection, content-length, transfer-encoding, keep-alive, upgrade), must not be content-type (the Response.contentType field is authoritative), and neither name nor value may contain CR, LF, or NUL (response splitting). The typed surface (withHeader in http.lg) rejects these with an Err up front; this filter is the defense-in-depth for maps poked directly.