feat(users): idioma por defecto con banderas SVG + conmutador coherente

- Campo "Idioma por defecto" al crear/editar usuario (columna locale ya existente),
  como desplegable Alpine con banderas SVG reales (no emoji, que en Windows se ven
  como "ES"/"GB") servidas localmente: public/images/flags/{es,gb}.svg.
- User: locale añadido a fillable. UserForm: propiedad/validación/guardado de locale.
- LanguageSwitcher de la cabecera usa las mismas banderas SVG.
- Regla CSS [x-cloak] en el layout para evitar parpadeo de desplegables Alpine.

Tests: UserLocaleTest (2) — crear/editar persisten el idioma.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

resources/views/layouts/app.blade.php

@@ -15,6 +15,9 @@
         @vite(['resources/css/app.css', 'resources/js/app.js'])
         @livewireStyles
 
+        {{-- Evita el parpadeo de elementos Alpine (x-cloak) antes de inicializar --}}
+        <style>[x-cloak]{display:none !important;}</style>
+
         <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css"
             integrity="sha256-p4NxAoJBhIIN+hmNHrzRCf9tD/miZyoHS5obTRR9BMY="
             crossorigin=""/>

resources/views/livewire/language-switcher.blade.php

@@ -1,10 +1,12 @@
 <div class="flex items-center gap-1"
      x-on:locale-changed.window="window.location.reload()">
-    @foreach(['en' => '🇬🇧 EN', 'es' => '🇪🇸 ES'] as $code => $label)
+    @foreach(['es' => ['flag' => 'es.svg', 'label' => 'ES'], 'en' => ['flag' => 'gb.svg', 'label' => 'EN']] as $code => $lang)
         <button wire:click="switchLanguage('{{ $code }}')"
-                class="btn btn-xs {{ $currentLocale === $code ? 'btn-primary' : 'btn-ghost' }}"
+                class="btn btn-xs gap-1.5 {{ $currentLocale === $code ? 'btn-primary' : 'btn-ghost' }}"
                 title="{{ __('Language') }}: {{ __($code === 'en' ? 'English' : 'Spanish') }}">
-            {{ $label }}
+            <img src="{{ asset('images/flags/' . $lang['flag']) }}"
+                 class="w-4 h-auto rounded-sm border border-base-300" alt="{{ $lang['label'] }}">
+            {{ $lang['label'] }}
         </button>
     @endforeach
 </div>

resources/views/livewire/user-form.blade.php

@@ -291,6 +291,46 @@
                             @error('formRole') <p class="text-error text-xs mt-1">{{ $message }}</p> @enderror
                         </div>
                     </div>
+
+                    <div class="flex items-start gap-4 mt-4">
+                        <label class="w-48 shrink-0 pt-2 text-sm font-medium text-gray-700">
+                            Idioma por defecto <span class="text-error">*</span>
+                            <p class="text-xs text-gray-400 font-normal mt-0.5">Idioma de la interfaz para este usuario</p>
+                        </label>
+                        <div class="flex-1">
+                            <div x-data="{ open: false }" @click.outside="open = false" class="relative w-full max-w-xs">
+                                {{-- Trigger: muestra la bandera + nombre del idioma seleccionado --}}
+                                <button type="button" @click="open = !open"
+                                        class="select select-bordered w-full flex items-center gap-2 text-left">
+                                    @foreach($languages as $code => $lang)
+                                        <span x-show="$wire.locale === '{{ $code }}'" class="flex items-center gap-2">
+                                            <img src="{{ asset('images/flags/' . $lang['flag']) }}"
+                                                 class="w-5 h-auto rounded-sm border border-base-300" alt="{{ $lang['name'] }}">
+                                            {{ $lang['name'] }}
+                                        </span>
+                                    @endforeach
+                                </button>
+
+                                {{-- Opciones --}}
+                                <ul x-show="open" x-transition x-cloak
+                                    class="absolute z-50 mt-1 w-full bg-base-100 border border-base-300 rounded-box shadow-lg p-1">
+                                    @foreach($languages as $code => $lang)
+                                        <li>
+                                            <button type="button"
+                                                    @click="$wire.set('locale', '{{ $code }}'); open = false"
+                                                    class="w-full flex items-center gap-2 px-3 py-2 rounded-lg hover:bg-base-200 text-left"
+                                                    :class="$wire.locale === '{{ $code }}' ? 'bg-base-200 font-medium' : ''">
+                                                <img src="{{ asset('images/flags/' . $lang['flag']) }}"
+                                                     class="w-5 h-auto rounded-sm border border-base-300" alt="{{ $lang['name'] }}">
+                                                {{ $lang['name'] }}
+                                            </button>
+                                        </li>
+                                    @endforeach
+                                </ul>
+                            </div>
+                            @error('locale') <p class="text-error text-xs mt-1">{{ $message }}</p> @enderror
+                        </div>
+                    </div>
                 </div>
 
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