fix(app): restore combobox flash prevention condition

The `referenceAtOrigin` check in `hasResolvedDesktopPosition` was
accidentally inverted during the provider profiles refactor (6f280276).
`!referenceAtOrigin` made the condition trivially true for all normal
triggers, letting the dropdown show at (0,0) before floating-ui resolved
the real position — visible as a left-side flash on the very first open.

packages/app/src/components/ui/combobox.tsx

@@ -440,7 +440,7 @@ export function Combobox({
         ? clampedMeasuredTopStartLeft !== null && measuredTopStartBottom !== null
         : floatingLeft !== null &&
           floatingTop !== null &&
-          (hasNonZeroFloatingPosition || !referenceAtOrigin));
+          (hasNonZeroFloatingPosition || referenceAtOrigin));
   const shouldHideDesktopContent = desktopPreventInitialFlash && !hasResolvedDesktopPosition;
   const shouldUseDesktopFade = !desktopPreventInitialFlash;