Add version/build-date status bar to dashboard footer

Agent-Logs-Url: https://github.com/christianlouis/InboxConverge/sessions/9efbf677-2d92-487b-abae-9adf0c728f88

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

frontend/src/lib/api.ts

@@ -755,4 +755,18 @@ export const adminNotificationsApi = {
   },
 };
 
+// ── Version API ─────────────────────────────────────────────────────────
+
+export interface VersionInfo {
+  version: string;
+  build_date: string | null;
+}
+
+export const versionApi = {
+  async get(): Promise<VersionInfo> {
+    const response = await api.get<VersionInfo>('/version');
+    return response.data;
+  },
+};
+
 export default api;