feat(web): highlight the offending field on a set_fields 422 (#28)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/objects/object-form.tsx

@@ -1,3 +1,4 @@
+import { useEffect } from "react";
 import { useForm } from "react-hook-form";
 import { useTranslation } from "react-i18next";
 
@@ -47,12 +48,14 @@ export function ObjectForm({
   onSubmit,
   onCancel,
   formError,
+  fieldErrorKey,
 }: {
   mode: "create" | "edit";
   defaults?: { core: ObjectCore; fields: Record<string, unknown> };
   onSubmit: (values: ObjectFormValues) => void;
   onCancel: () => void;
   formError?: string | null;
+  fieldErrorKey?: string | null;
 }) {
   const { t } = useTranslation();
 
@@ -68,6 +71,15 @@ export function ObjectForm({
 
   const { register, handleSubmit, formState: { errors } } = form;
 
+  useEffect(() => {
+    if (fieldErrorKey) {
+      form.setError(`fields.${fieldErrorKey}` as never, {
+        type: "server",
+        message: t("form.fieldRejected", { field: fieldErrorKey }),
+      });
+    }
+  }, [fieldErrorKey, form, t]);
+
   const submit = handleSubmit((data) => {
     const fields = pruneFields(data.fields);
 
@@ -149,7 +161,7 @@ export function ObjectForm({
 
               {errors.fields?.[def.key] && (
                 <p role="alert" className="text-xs text-red-600">
-                  {t("form.required")}
+                  {errors.fields[def.key]?.message ?? t("form.required")}
                 </p>
               )}
             </div>