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/[id]/edit.vue

@@ -512,6 +512,16 @@
             Enregistrer les modifications
           </button>
         </div>
+
+        <!-- Comments -->
+        <div class="mt-4">
+          <CommentSection
+            entity-type="composant"
+            :entity-id="String(route.params.id)"
+            :entity-name="component?.name"
+            show-resolved
+          />
+        </div>
       </div>
     </section>
   </main>