Function deserialize_header_map_spec 

pub fn deserialize_header_map_spec(buf: &[u8]) -> Option<Vec<(String, String)>>

Deserialize a spec/SDK proxy-wasm wire-layout header map (the format serialize_header_map_spec produces and the Rust proxy-wasm SDK’s utils::deserialize_map, hostcalls.rs ~line 1305, parses). An empty buffer is an empty map (the SDK’s convention); any truncated or corrupt buffer returns None (the SDK would panic on its unwraps — the host fails the hostcall instead).