Option to change log format to JSON

First off, thank you for putting in the work. This is a super helpful project.

I would appreciate it if it was possible to enable an option besides LOG_WITHOUT_NEWLINE and DISABLE_REQUEST_LOGS to have one line per request in the log output formatted as JSON.

One of the reasons is that I don't use the logs on the host machine directly. They might get scraped and processed out of order by Loki, so they might not end up next to each other. The second reason is that it would be simpler to parse them when they had the same format.

先定位現有的 LOG_WITHOUT_NEWLINE 和 DISABLE_REQUEST_LOGS 選項，並追蹤請求記錄路徑。新增一種可選的 JSON 格式，讓每個請求輸出一行，然後確認輸出始終可解析，並保留所要求的記錄資訊。