Hide top nav on mobile, add "Plus" sheet to bottom tab bar

The top nav (logo + hamburger) was still sm:hidden-only on its inner
sections but the <nav> element itself had no breakpoint class, so it
kept rendering as an empty-looking bar above the new bottom tab bar.
Hide the whole element below sm and drop the now-dead hamburger/Alpine
toggle and its responsive menu, since nothing renders it anymore.

Account/settings links (Profile, Foyer, Catégories, Récurrences,
Log Out) that used to live in that hamburger now live in a "Plus"
slide-up sheet on the bottom tab bar. Logging out needed a real route
since the sheet isn't a Livewire component and can't call the
Volt navigation component's method directly.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

routes/web.php

@@ -1,5 +1,6 @@
 <?php
 
+use App\Livewire\Actions\Logout;
 use App\Livewire\Categories\Index as CategoriesIndex;
 use App\Livewire\Dashboard\Index as DashboardIndex;
 use App\Livewire\Household\AcceptInvite;
@@ -52,4 +53,10 @@ Route::get('recurrences', RecurringIndex::class)
 Route::get('invites/{token}', AcceptInvite::class)
     ->name('invites.accept');
 
+Route::post('logout', function (Logout $logout) {
+    $logout();
+
+    return redirect('/');
+})->middleware(['auth'])->name('logout');
+
 require __DIR__.'/auth.php';