waitForPhotoUpload waits on FilePond processing-complete; AE1/AE4 use
input.filepond--browser + the .photo-convert-status error status; V3/V4 back
to FilePond limit + non-image rejection; reauth hint -> .photo-reauth-hint;
test-form-config asserts type:filepond. Verified against a live server via a
browser smoke run (HEIC->JPEG attach, corrupt fail-closed, draft restore).