feat: enhance export and import workflows with improved error handling and notifications

static/js/imports.js

@@ -95,6 +95,11 @@ document.addEventListener("DOMContentLoaded", () => {
       uploadButton.classList.add("loading");
 
       // Actual upload logic handled separately (e.g., fetch).
+      NotificationCenter?.show({
+        message: "Upload started…",
+        level: "info",
+        timeout: 2000,
+      });
     });
   });
 });