feat(permissions) : add role-based UI guards and readonly mode for viewers

- Add usePermissions composable (isAdmin, canEdit, canView)
- Password-protected profile login with modal on profiles page
- Disable all form fields for ROLE_VIEWER across edit/create pages
- Show navigation buttons (Modifier/Consulter) for all roles, hide delete for viewers
- Add readonly prop to ModelTypeForm for category pages
- Disable modal fields (sites, constructeurs) for viewers
- Guard /admin routes in middleware

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/components/sites/SiteEditModal.vue

@@ -2,7 +2,7 @@
   <div v-if="visible" class="modal modal-open">
     <div class="modal-box max-w-md">
       <h3 class="font-bold text-lg mb-4">
-        Modifier le site
+        {{ disabled ? 'Détails du site' : 'Modifier le site' }}
         <span v-if="siteName" class="block text-sm font-normal text-gray-500">{{ siteName }}</span>
       </h3>
       <form class="space-y-4" @submit.prevent="emit('submit')">
@@ -15,11 +15,12 @@
             type="text"
             placeholder="Nom du site"
             class="input input-bordered"
+            :disabled="disabled"
             required
           >
         </div>
 
-        <SiteContactFormFields :form="props.form" />
+        <SiteContactFormFields :form="props.form" :disabled="disabled" />
 
         <div class="border-t border-base-200 pt-4 space-y-4">
           <div class="flex items-center justify-between">
@@ -37,6 +38,7 @@
           </div>
 
           <DocumentUpload
+            v-if="!disabled"
             v-model="selectedFilesModel"
             title="Déposer vos fichiers"
             subtitle="Formats courants acceptés : PDF, JPG, PNG, DOCX..."
@@ -90,7 +92,7 @@
                   <button type="button" class="btn btn-ghost btn-xs" @click="emit('download-document', document)">
                     Télécharger
                   </button>
-                  <button type="button" class="btn btn-error btn-xs" @click="emit('remove-document', document.id)">
+                  <button v-if="!disabled" type="button" class="btn btn-error btn-xs" @click="emit('remove-document', document.id)">
                     Supprimer
                   </button>
                 </div>
@@ -103,7 +105,7 @@
           <button type="button" class="btn" @click="emit('close')">
             Annuler
           </button>
-          <button type="submit" class="btn btn-primary" :disabled="uploadingDocuments">
+          <button type="submit" class="btn btn-primary" :disabled="disabled || uploadingDocuments">
             <span v-if="uploadingDocuments" class="loading loading-spinner loading-xs mr-2" />
             Enregistrer
           </button>
@@ -155,6 +157,10 @@ const props = defineProps({
   formatSize: {
     type: Function,
     required: true
+  },
+  disabled: {
+    type: Boolean,
+    default: false
   }
 })