refactor(ui) : improve styling, layout and responsive across all components

Rework CSS theme (app.css), navbar layout, dashboard page, machine detail,
catalog pages, and various form/display components for better consistency
and mobile responsiveness.

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

app/pages/component/[id]/edit.vue

@@ -1,11 +1,12 @@
 <template>
-  <DocumentPreviewModal
-    :document="previewDocument"
-    :visible="previewVisible"
-    :documents="componentDocuments"
-    @close="closePreview"
-  />
-  <main class="container mx-auto px-6 py-10">
+  <div>
+    <DocumentPreviewModal
+      :document="previewDocument"
+      :visible="previewVisible"
+      :documents="componentDocuments"
+      @close="closePreview"
+    />
+    <main class="container mx-auto px-6 py-10">
     <div v-if="loading" class="flex flex-col items-center gap-4 py-20 text-center">
       <span class="loading loading-spinner loading-lg" aria-hidden="true" />
       <p class="text-sm text-base-content/70">Chargement du composant…</p>
@@ -269,7 +270,8 @@
         </div>
       </div>
     </section>
-  </main>
+    </main>
+  </div>
 </template>
 
 <script setup lang="ts">