Remove raw error responses from server

[Iron-56]

p5.js version

any

What is your operating system?

None

Web browser and version

No response

Actual Behavior

In many files, the server responds with raw errors using res.status(500).json({ error: err }) which could leak internal stack traces, internal DB messages or sensitive information.

Expected Behavior

Return a simple message instead of returning the stack trace: res.status(500).json({ error: 'Internal server error' });

Steps to reproduce

Uncaught errors in the code which are caught using these code could respond with sensitive info