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-new-page.tsx

@@ -3,7 +3,7 @@ import { useNavigate } from "react-router-dom";
 import { useTranslation } from "react-i18next";
 
 import { ObjectForm, type ObjectFormValues } from "./object-form";
-import { useCreateObject, useSetFields } from "../api/queries";
+import { useCreateObject, useSetFields, FieldRejection } from "../api/queries";
 
 export function ObjectNewPage() {
   const { t } = useTranslation();
@@ -32,8 +32,9 @@ export function ObjectNewPage() {
     if (Object.keys(values.fields).length > 0) {
       try {
         await setFields.mutateAsync({ id, fields: values.fields });
-      } catch {
-        navigate(`/objects/${id}/edit`, { state: { fieldsError: true } });
+      } catch (e) {
+        const fieldErrorKey = e instanceof FieldRejection ? e.field : undefined;
+        navigate(`/objects/${id}/edit`, { state: { fieldsError: true, fieldErrorKey } });
         return;
       }
     }