feat(comments): add comment/ticket system across all entity pages

Add CommentSection component for inline comments on entity detail pages
(machines, pieces, composants, products, categories, skeleton types).
Add dedicated /comments page with filters, pagination and clickable links.
Add unresolved count badge on avatar and in profile dropdown.

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

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

@@ -35,6 +35,16 @@
         @cancel="handleCancel"
       />
     </section>
+
+    <!-- Comments -->
+    <div class="mt-4">
+      <CommentSection
+        entity-type="component_category"
+        :entity-id="String(route.params.id)"
+        :entity-name="initialData?.name"
+        show-resolved
+      />
+    </div>
   </main>
 </template>