fix(categories): add safe null guards on allowedParentOptions and enable parent selection in NewCategory.tsx

src/features/categories/pages/NewCategory.tsx

@@ -113,8 +113,11 @@ export default function NewCategory() {
   }, [isEdit, id, categories, parentIdParam]);
 
   const allowedParentOptions = useMemo(() => {
-    if (!isEdit) return categories;
-    return categories.filter((cat) => cat.id !== id && !cat.path?.startsWith(categories.find(c => c.id === id)?.path + "/"));
+    const validCategories = Array.isArray(categories) ? categories.filter((cat) => cat && cat.id) : [];
+    if (!isEdit) return validCategories;
+    const currentCat = validCategories.find((c) => c.id === id);
+    const currentPath = currentCat?.path || "";
+    return validCategories.filter((cat) => cat.id !== id && (!currentPath || !cat.path?.startsWith(currentPath + "/")));
   }, [categories, isEdit, id]);
 
   return (
@@ -204,16 +207,16 @@ export default function NewCategory() {
                     name="parentId"
                     value={formik.values.parentId}
                     onChange={formik.handleChange}
-                    disabled={!isEdit} // Disabled (Read-only) during creation, enabled during Edit
+                    disabled={Boolean(parentIdParam)}
                   >
                     <option value="">None (Root Level)</option>
-                    {allowedParentOptions.map((cat) => (
+                    {allowedParentOptions.filter(Boolean).map((cat) => (
                       <option key={cat.id} value={cat.id}>
                         {cat.name} ({cat.code})
                       </option>
                     ))}
                   </Select>
-                  {!isEdit && (
+                  {!isEdit && Boolean(parentIdParam) && (
                     <p className="text-[10px] text-muted-foreground mt-1">
                       Locked to parent context. Click inline tree actions to create subcategories.
                     </p>