Add detailed log view

Discussed on the dev call, we may want to investigate the behavior of new features and clients from the app itself. The Breez app had a similar feature where a simple tab opened a log file. I think it would be nice to do the same here and write events out to something like `debug.log` which may be opened in the settings page.

该 issue 未指定文件、测试或入口点。首先定位设置页面和应用当前的事件处理方式，然后明确 debug.log 的日志格式、存储方式和查看行为。当应用记录相关事件并能从设置中提供详细日志时，即视为完成。

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