Function classify_json_text 

pub fn classify_json_text(text: &str) -> JsonClass

Classify a JSON document: a PowerIO IR module or a case document across the transmission and distribution domains.

PowerIO IR is recognized by its schema: "pio-ir" header. For a case, Unknown means there is no recognized top level marker, and Ambiguous means the document contains strong markers from both domains, so the caller must ask the user for an explicit format.