  We report the first (in)elastic scattering measurement of
$^{25}\mathrm{Al}+p$ with the capability to select and measure in a broad
energy range the proton resonances in $^{26}$Si contributing to the
$^{22}$Mg$(\alpha,p)$ reaction at type I x-ray burst energies. We measured
spin-parities of four resonances above the $\alpha$ threshold of $^{26}$Si that
are found to strongly impact the $^{22}$Mg$(\alpha,p)$ rate. The new rate
advances a state-of-the-art model to remarkably reproduce light curves of the
GS 1826$-$24 clocked burster with mean deviation $<9$ % and permits us to
discover a strong correlation between the He abundance in the accreting
envelope of photospheric radius expansion burster and the dominance of
$^{22}$Mg$(\alpha,p)$ branch.
