  We measured the $^{57}$Zn $\beta$-delayed proton ($\beta$p) and $\gamma$
emission at the National Superconducting Cyclotron Laboratory. We find a
$^{57}$Zn half-life of 43.6 $\pm$ 0.2 ms, $\beta$p branching ratio of (84.7
$\pm$ 1.4)%, and identify four transitions corresponding to the exotic
$\beta$-$\gamma$-$p$ decay mode, the second such identification in the $f
p$-shell. The $p/\gamma$ ratio was used to correct for isospin mixing while
determining the $^{57}$Zn mass via the isobaric multiplet mass equation.
Previously, it was uncertain as to whether the rp-process flow could bypass the
textbook waiting point $^{56}$Ni for astrophysical conditions relevant to
Type-I X-ray bursts. Our results definitively establish the existence of the
$^{56}$Ni bypass, with 14-17% of the $rp$-process flow taking this route.
