asconfig.json: output compiler warnings and errors to file

Hi!

When working with AI tools like Gemini CLI, I often need to copy compiler warnings and errors into the chat. Could you add an option to automatically output them to a specified file, so AI agents can read and fix warnings and errors directly?

Thanks!

Start with the asconfig.json configuration and locate how compiler warnings and errors are collected. Define how a specified output file should be configured, then verify that warnings and errors are written there for AI tools to read.

Written by the indexing model from the issue text.