Refactor error and confirmation handling in membership application management; replace alerts with modal dialogs for improved user experience. Update application status to 'approved' for a new member and add corresponding data to JSON files.

server/data/membership-applications/1761225990109.json

@@ -0,0 +1,15 @@
+{
+  "id": "1761225990109",
+  "timestamp": "2025-10-23T13:26:30.166Z",
+  "status": "pending",
+  "metadata": {
+    "mitgliedschaftsart": "aktiv",
+    "isVolljaehrig": true,
+    "pdfGenerated": true
+  },
+  "personalData": {
+    "nachname": "Test",
+    "vorname": "Modal",
+    "email": "modal@test.de"
+  }
+}