feat(wizard): cache مشخصه globally instead of per topic/category/brand

The specs combobox drew only from materials in the selected topic, further
narrowed by the row's category and brand, so a spec was offered only when
some material in that topic shared the same category AND brand. On a new
quote the user therefore lost specs recorded in earlier quotes.

- api.specsList(): new global source reading the attribute-definitions
  registry (topic/category/brand independent)
- materialOptions('spec'): unions the registry, specs of all materials,
  and specs typed in sibling rows — no topic/category/brand filter
- EditModal: same global registry added to its spec options

Verified the registry endpoint returns labels and that the union includes
specs absent from material attributes (e.g. 'مسی').

frontend/src/pages/Dashboard/EditModal.tsx

@@ -112,13 +112,24 @@ export function EditModal({ quoteId, onClose }: EditModalProps) {
     }
   };
 
-  // گزینه‌های مشخصه — همه‌ی مشخصه‌های ثبت‌شده (کش)
+  // گزینه‌های مشخصه — همه‌ی مشخصه‌های ثبت‌شده (کش) + رجیستری سراسری
+  const [globalSpecs, setGlobalSpecs] = useState<string[]>([]);
+  useEffect(() => {
+    let alive = true;
+    void api
+      .specsList()
+      .then((list) => alive && setGlobalSpecs(list))
+      .catch(() => {});
+    return () => { alive = false; };
+  }, []);
+
   const specOptions = useMemo(() => {
     const set = new Set<string>();
+    globalSpecs.forEach((s) => s && set.add(s));
     materials.forEach((m) => (m.specs || []).forEach((s) => s && set.add(s)));
     itemRows.forEach((r) => r.specs.forEach((s) => s && set.add(s)));
     return [...set].sort((a, b) => a.localeCompare(b, "fa"));
-  }, [materials, itemRows]);
+  }, [materials, itemRows, globalSpecs]);
 
   // گزینه‌های پروژه — پروژه‌های ثبت‌شده + پروژه‌های خود پیشنهاد
   const projectOptions = useMemo(() => {