CRITICAL: replace `lg:hidden` on PrimeVue Drawer with `v-if="isMobile"` so the
teleported portal/overlay is never created on desktop viewports regardless of
mobileOpen state. Replace useMediaQuery raw string in SidebarHeader with
useBreakpoints(breakpointsTailwind).smaller('lg') shared by both components.
Add desktop/mobile comments; adapt tests to useBreakpoints mock; add
Drawer-absent-on-desktop and aside w-16/w-64 width-class assertions (21 tests).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>