Add file output, clean up stack traces, and update docs

[FourierTransformer]

Changes

• Can now output test results to files at the end of a run
• stack traces are a little nicer for errors that throw objects (stacktrace includes line numbers now!)
• ability to catch as many Lua exit patterns as possible

AI Disclosure: I was really hoping AI would be able to handle adding the file output, but even with prompting it could not re-use the existing formatter cleanly. In the end, I wrote most of the code for it and the docs. AI wrote many of the test cases and helped looking into the debug module. Also, AI could not get to the bottom of the Lua 5.1/LuaJIT issue and I had to step in to debug it.

It truly does sometimes seem great and other times feel severely lacking. Like it can do easy tedious things, but not think clearly.