New: Find a Mentor, a goal-first way to get matched

There's a new way to find a mentor: instead of scrolling the full directory first, tell us what you're trying to accomplish and we'll recommend a handful of mentors who fit, each with a real, specific reason: a shared topic focus, a language match, or being in your timezone. If nothing matches strongly, we say so plainly instead of making something up.

The full mentor directory hasn't gone anywhere. It's linked right from the new page for anyone who'd rather browse first, and it's still in the main nav too.

This builds directly on last week's update to the mentor contact form. Once you find someone who looks like a fit, the same structured "what are you trying to accomplish" request flow is right there on their profile.