The paranoia of "my idea is being stolen" is the sign of a highly inexperienced person and also statistically speaking, the sign of someone who is unlikely to succeed. Your skills as a designer and implementer make you highly valuable to many non-technical founders, so you should consider yourself able to pick your partners, and not have to "settle." An idea is worth *nothing* without execution, so I'd suggest that you align yourself with a more experienced founder.

Happy to talk through this and more details in a call. I'd also caution you that a contract doesn't provide you full security against this person's deceitfulness or bad behavior.