feat(catalog): add description column with hover popover + skeleton edit guard

- Add description column to pieces and component catalog tables
- Show full text in a popover on hover for truncated descriptions
- Block skeleton editing when machines are linked (warning alert)

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

app/pages/component-catalog.vue

@@ -116,6 +116,7 @@
                   <th class="w-24">Aperçu</th>
                   <th>Nom</th>
                   <th>Référence</th>
+                  <th>Description</th>
                   <th>Type de composant</th>
                   <th>Actions</th>
                 </tr>
@@ -130,6 +131,15 @@
                   </td>
                   <td>{{ component.name || 'Composant sans nom' }}</td>
                   <td>{{ component.reference || '—' }}</td>
+                  <td class="max-w-xs">
+                    <div v-if="component.description" class="group relative">
+                      <span class="block cursor-help truncate">{{ component.description }}</span>
+                      <div class="pointer-events-none invisible absolute left-0 top-full z-50 mt-1 max-w-sm overflow-hidden rounded-lg border border-base-300 bg-base-100 p-3 text-sm shadow-lg group-hover:pointer-events-auto group-hover:visible">
+                        <p class="break-words whitespace-pre-wrap">{{ component.description }}</p>
+                      </div>
+                    </div>
+                    <span v-else>—</span>
+                  </td>
                   <td>
                     <NuxtLink
                       v-if="component.typeComposant?.id"