Both "will you" and "won't you" would be correct according to modern day linguistics. "Shan't" and "shall" would be grammatically incorrect in the sentence you have written because "come here" is a command directed towards the 2nd person (i.e. Singular you or plural you all) and not the 1st (i.e. Singular I or plural we). One wouldn't say "come here, we" or "come here, her".