feat: Enhance user group management and transaction handling in stored procedures

- Improved user group deletion logic to accurately report success or failure.
- Updated user group renaming checks to prevent unintended inserts or updates.
- Added documentation on transaction blocking risks during full resets in stored procedures.
- Removed unnecessary login scripts from database project.

Fuchs/js/intranet/modules/fis.usr.js

@@ -49,14 +49,18 @@ let $usr = {
     },
     /* Re-fetches a single user and swaps its grid row in place, keeping selection + ribbon
        (used after changes that only affect that one row: email, group membership). Falls back
-       to a full reload when the row is no longer in the grid. */
+       to a full reload when the row is no longer in the grid. Looks up the current row node by
+       id inside the response handler (not before the request) so two overlapping calls — e.g.
+       two quick checkbox toggles in groupsDlg — each replace whatever row is live at the time
+       their own response arrives, instead of the second call operating on a node the first
+       already detached via replaceWith. */
     refreshRow: function (rw) {
-        let old = $('#usr' + rw.useraccount_id);
-        if (old.length === 0) { $usr.renderLst(); return; }
+        if ($('#usr' + rw.useraccount_id).length === 0) { $usr.renderLst(); return; }
         $ocms.postXT({
             url: $ocms.url('usr/list'), data: { useraccount_id: rw.useraccount_id }, success: function (r) {
                 let fresh = (r.users || [])[0];
-                if (!fresh) { $usr.renderLst(); return; }
+                let old = $('#usr' + rw.useraccount_id);
+                if (!fresh || old.length === 0) { $usr.renderLst(); return; }
                 let selected = old.is('.selected');
                 let row = $usr.buildRow(fresh).toggleClass('selected', selected);
                 old.replaceWith(row);