fix(appshell): wrap PrimeVue responsive elements to bypass specificity conflict

Tailwind's lg:hidden loses to PrimeVue's .p-button { display: inline-flex }
due to equal specificity but later cascade order. Resulted in the mobile
hamburger remaining visible on desktop, allowing the Drawer to open over
the already-visible permanent sidebar.

Fix: wrap mobile-only cluster (hamburger + title) in a plain <div lg:hidden>
so the wrapper owns the visibility toggle. The wrapper is not a PrimeVue
component, so no specificity competition.

The Drawer itself had the same anti-pattern (class="lg:hidden") and is
worse, because PrimeVue Drawer teleports to body — a wrapping div on the
parent does not isolate the teleported overlay, and a class on the Drawer
root loses to .p-drawer { display: flex } when visible. Converted to
v-if="!isLg" driven by useMediaQuery('(min-width: 1024px)'). Vue simply
does not render the component on lg+, so no display rule competes.

Audited all 5 layouts for the same anti-pattern:
- AppShell.vue — fixed (Button + Drawer described above)
- default.vue / OrganizerLayout.vue / PortalLayout.vue — delegate to
  AppShell; no PrimeVue elements with responsive classes
- blank.vue — plain <div>, no PrimeVue
- PublicLayout.vue — plain <main>, no PrimeVue

useMediaQuery is auto-imported via unplugin-auto-import's @vueuse/core
entry in vite.config.ts; explicit imports get stripped by the post-edit
ESLint --fix hook as redundant.

F3-introduced bug (commit 43915501); surfaced during F3.5 testing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/app/src/layouts/components/AppShell.vue

@@ -52,6 +52,13 @@ const authStore = useAuthStore()
 
 const mobileNavOpen = ref(false)
 
+// Tailwind's lg breakpoint, mirrored in script so Vue can own the
+// visibility of PrimeVue elements that would otherwise lose a CSS
+// specificity duel to .p-button / .p-drawer / etc. See the wrapper
+// `<div class="lg:hidden">` around the topbar mobile cluster and the
+// `v-if="!isLg"` on the Drawer.
+const isLg = useMediaQuery('(min-width: 1024px)')
+
 function isHeading(item: NavItem): item is NavHeading {
   return 'heading' in item
 }
@@ -143,11 +150,16 @@ function onHelpClick() {
       <SidebarUserCard />
     </aside>
 
-    <!-- Mobile drawer (overlay, <lg) -->
+    <!--
+      Mobile drawer (overlay, <lg). v-if (not lg:hidden class) because
+      PrimeVue Drawer teleports to body, so a wrapping div or class
+      on the Drawer root can't beat .p-drawer's display rule in the
+      cascade — Vue must simply not render the component on lg+.
+    -->
     <Drawer
+      v-if="!isLg"
       v-model:visible="mobileNavOpen"
       position="left"
-      class="lg:hidden"
       :pt="{
         root: { style: { width: '18rem' } },
         header: { class: 'p-0' },
@@ -190,20 +202,27 @@ function onHelpClick() {
       <!-- Top bar -->
       <header class="flex h-16 items-center justify-between border-b border-surface-200 bg-surface-0 px-4">
         <div class="flex items-center gap-2">
-          <Button
-            class="lg:hidden"
-            severity="secondary"
-            text
-            rounded
-            aria-label="Menu openen"
-            @click="mobileNavOpen = true"
-          >
-            <Icon
-              name="tabler-menu-2"
-              size="24"
-            />
-          </Button>
-          <span class="text-base font-medium text-surface-700 lg:hidden">{{ title }}</span>
+          <!--
+            Mobile cluster: visibility owned by this plain DIV. The
+            PrimeVue Button alone with lg:hidden loses to
+            .p-button { display: inline-flex } in the cascade — same
+            specificity, PrimeVue's stylesheet loads later.
+          -->
+          <div class="flex items-center gap-2 lg:hidden">
+            <Button
+              severity="secondary"
+              text
+              rounded
+              aria-label="Menu openen"
+              @click="mobileNavOpen = true"
+            >
+              <Icon
+                name="tabler-menu-2"
+                size="24"
+              />
+            </Button>
+            <span class="text-base font-medium text-surface-700">{{ title }}</span>
+          </div>
           <nav
             class="hidden items-center gap-2 text-sm lg:flex"
             aria-label="Kruimelpad"