Replace screen.width with window.innerWidth in useMobile composable.
screen.width reports the physical screen size (0 in headless Chromium),
while window.innerWidth reflects the actual viewport — the correct metric
for responsive layout. The previous Object.defineProperty workaround in
wallet-provider.ts could not override the native Screen.prototype getter,
so screen.width remained 0, isMobile stayed true, and ConnectButton was
never rendered. Fix wallet-provider.ts to pass viewport/screen options
directly to browser.newContext() and remove the broken init-script shim.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
