JSON Repair and Parsing

This tool robustly repairs and interprets malformed JSON-like strings and converts them into strict, parseable JSON that conforms to a system-provided structured output schema. It accepts a single input parameter json_str, which is a raw text string that may include Markdown code fences, comments, trailing commas, or other nonstandard syntax around otherwise JSON data. The worker must parse and clean json_str, infer the intended structured data, and then return only syntactically valid JSON that strictly validates against the system-provided structured output schema (auto-produced, not supplied here), without adding extraneous fields or unsupported values.