feat: Add random path probing to bypass Next.js middleware redirects

[fatguru]

Hi Team,

This PR addresses False Negatives caused by middleware.ts redirects on the root path (/).

The Problem:
Currently, the scanner defaults to probing ["/"]. In many Next.js deployments, the root path redirects (e.g., 307 to /login). This redirection often strips the POST body before the RSC parser processes it, causing the scanner to miss vulnerable targets.

The Fix:
I updated the default logic to probe both / AND /{random_string}.
Hitting a non-existent path triggers the Next.js Global Not Found handler (which is an RSC). This forces the server to parse the payload regardless of authentication middleware or root redirects.

Issue associated: Fixes #27

Cheers!