feat(web): code-aware field errors + min count validation (#46)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/objects/object-edit-form.tsx

@@ -30,7 +30,12 @@ function ObjectEditFormLoaded({ object, id }: { object: AdminObjectView; id: str
   const update = useUpdateObject();
   const setFields = useSetFields();
 
-  const locationState = location.state as { fieldsError?: boolean; fieldErrorKey?: string } | null;
+  const locationState = location.state as {
+    created?: boolean;
+    fieldsError?: boolean;
+    fieldErrorKey?: string;
+    fieldErrorCode?: string;
+  } | null;
 
   const [error, setError] = useState<string | null>(() => {
     if (locationState?.fieldErrorKey) return t("form.fieldRejected", { field: locationState.fieldErrorKey });
@@ -42,6 +47,10 @@ function ObjectEditFormLoaded({ object, id }: { object: AdminObjectView; id: str
     locationState?.fieldErrorKey ?? null,
   );
 
+  const [fieldErrorCode, setFieldErrorCode] = useState<string | null>(
+    locationState?.fieldErrorCode ?? null,
+  );
+
   useBreadcrumb([
     { label: t("nav.objects"), to: "/objects" },
     { label: object.object_number, to: `/objects/${id}` },
@@ -64,6 +73,7 @@ function ObjectEditFormLoaded({ object, id }: { object: AdminObjectView; id: str
   const onSubmit = async (values: ObjectFormValues): Promise<boolean> => {
     setError(null);
     setFieldErrorKey(null);
+    setFieldErrorCode(null);
 
     try {
       await update.mutateAsync({ id, body: values.core });
@@ -71,6 +81,7 @@ function ObjectEditFormLoaded({ object, id }: { object: AdminObjectView; id: str
     } catch (e) {
       if (e instanceof FieldRejection) {
         setFieldErrorKey(e.field);
+        setFieldErrorCode(e.code);
         setError(t("form.fieldRejected", { field: e.field }));
       } else {
         setError(t("form.rejected"));
@@ -89,6 +100,7 @@ function ObjectEditFormLoaded({ object, id }: { object: AdminObjectView; id: str
       defaults={defaults}
       formError={error}
       fieldErrorKey={fieldErrorKey}
+      fieldErrorCode={fieldErrorCode}
       onSubmit={onSubmit}
       onCancel={() => navigate(`/objects/${id}`)}
     />