Add JSONC input mode for jq checks

[skovranek]

• Add inputMode: jsonc to stdoutJq checks, supporting line comments, block comments, and trailing commas.
• Normalize JSONC using HuJSON before passing it through the existing JSON decoder and jq evaluation.
• Preserve numeric precision and existing error reporting. JSON and JSONL modes remain unchanged.
• Accept a final line comment without a newline.