Hybrid sparrow?

I first pegged it as an immature white-crown. The beak is right, the head pattern seems right, at least from this angle. But the overall colour is too beige / brown, and those bright yellow slashes on the front edge of its wing say “golden-crowned” instead.

The two species are close cousins, and can apparently interbreed. Golden-crowns’ summer range is somewhat out of the Lower Mainland, but there are always vagrants!