Timekeeper Time Zone Converter

Converts a provided ISO 8601 timestamp or the current time into a specified target IANA time zone and returns normalized time details. Accepts iso_time (optional ISO 8601 date-time string), target_zone (required IANA time zone string), and source_zone (optional IANA time zone string used when iso_time has no embedded offset). The worker must use only these inputs and produce an output JSON object that strictly validates against the system-provided structured output schema for this tool, with correct types and no extra fields.