Let $f$ be a differentiable function defined on $\left[0,\dfrac{\pi}{2}\right]$ such that $f(x)>0$ and $f(x)+\displaystyle\int_0^x f(t)\sqrt{1-(\log_e f(t))^2}\,dt=e$, $\forall x\in\left[0,\dfrac{\pi}{2}\right]$. Then $\left(6\log_e f\!\left(\dfrac{\pi}{6}\right)\right)^2$ is equal to ___.