improve display of GetSessionError

src-tauri/src/errors.rs

@@ -57,8 +57,12 @@ where
     E: Error,
     M: serde::ser::SerializeMap,
 {
-    let src = err.source().map(|s| format!("{s}"));
-    map.serialize_entry("source", &src)
+    let msg = err.source().map(|s| format!("{s}"));
+    map.serialize_entry("msg", &msg)?;
+    map.serialize_entry("code", &None::<&str>)?;
+    map.serialize_entry("source", &None::<&str>)?;
+
+    Ok(())
 }