We see this all the time, that gay teens have crushes on their closest same-sex friends. They confuse this with sexual/dating affection. And sometimes it is. But a lot of times, it's not. But this is who you have got in front of you right now, who accepts you for who you are (I assume you are uncloseted, at least with her).
Next year, you will probably leave your town, either for work on an education or both, and you will meet more lesbians. The choices will become a lot broader, and you will have other opportunities for romance.
If she likes this guy, and he likes her, then they are probably going to date, or they will at least dance around it. You have to deal with that. She is an individual and is going to do what she wants in that area (BTW, I think there is an expiration date on the stupid bro code. Otherwise, no one would ever date anyone).
Does she like you romantically? You can always ask, but be prepared for the very real possibility that the friendship will end over that.
But I will tell you that what we also see is people like you who are essentially, and often unknowingly, being led on by people like her. She doesn't necessarily mean to confuse you or push your attraction buttons, but she is doing so by behaving as she would with a het female friend. And that ends up being unfair to you.
Maybe keep that in mind a bit as you consider how to react to the possibility of her dating someone other than you.