Smooth agent config save button state

ui/src/lib/issueDetailBreadcrumb.ts

@@ -0,0 +1,24 @@
+type IssueDetailBreadcrumb = {
+  label: string;
+  href: string;
+};
+
+type IssueDetailLocationState = {
+  issueDetailBreadcrumb?: IssueDetailBreadcrumb;
+};
+
+function isIssueDetailBreadcrumb(value: unknown): value is IssueDetailBreadcrumb {
+  if (typeof value !== "object" || value === null) return false;
+  const candidate = value as Partial<IssueDetailBreadcrumb>;
+  return typeof candidate.label === "string" && typeof candidate.href === "string";
+}
+
+export function createIssueDetailLocationState(label: string, href: string): IssueDetailLocationState {
+  return { issueDetailBreadcrumb: { label, href } };
+}
+
+export function readIssueDetailBreadcrumb(state: unknown): IssueDetailBreadcrumb | null {
+  if (typeof state !== "object" || state === null) return null;
+  const candidate = (state as IssueDetailLocationState).issueDetailBreadcrumb;
+  return isIssueDetailBreadcrumb(candidate) ? candidate : null;
+}