Function export_mem_to_bytes 

pub fn export_mem_to_bytes(
    mem_dir: &Path,
    config: &MemConfig,
    workspace_root: Option<&Path>,
    workspace_schemas_dir: Option<&Path>,
    explicit_name: &str,
) -> Result<MemExportBytes, MemExportError>

Produce a portable .mem archive as bytes for a folder-backed mem. Same wire format as export_mem — same whitelist projection, same embedded schema source, same deterministic sort order and fixed mtime — but the output stays in memory so the bridge / WASM consumers can return it directly over HTTP.

explicit_name is the mem name the publish whitelist receives. Callers reaching this through crate::Engine::export_mem_to_bytes pass the mount’s mem name; callers reaching it directly choose the disk basename or a config-supplied alias.