test(post-form): realign photo specs to FilePond after U4 rework

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).

scripts/test-form-config.sh

@@ -63,9 +63,9 @@ check_grep "hero_image field present"       "name: hero_image"
 check_grep "force_connect field present"    "name: force_connect"
 check_grep "featured field present"         "name: featured"
 
-# Photos must use the custom controlled picker (U4), not filepond/file — that is
-# what lets post-form.js convert HEIC before upload.
-check_grep "photos field uses the custom 'photos' type (HEIC pipeline)" "type: photos"
+# Photos use Grav's filepond field; post-form.js hooks its beforeAddFile to
+# convert HEIC->JPEG before FilePond uploads (U4).
+check_grep "photos field uses the filepond type" "type: filepond"
 
 echo "────────────────────────────────────────"
 echo "  $PASS passed, $FAIL failed"