The getState() resolver hard-references Backstage\Media\Models\Media
and Backstage\UploadcareField\Uploadcare (Factory). Both live in
separate packages that are not declared as requires, so installing
filament-uploadcare-field standalone (state = plain CDN URLs) crashes
with "Class not found" the moment the field is rendered.

Guard the resolver call with class_exists() checks. When the CMS
packages are absent, items pass through unchanged — matching v1.x
behaviour for non-CMS consumers.