fix(centralui): stabilize audit grid th nodes with @key; doc grid limitations

src/ScadaLink.CentralUI/wwwroot/js/audit-grid.js

@@ -171,6 +171,12 @@ window.auditGrid = {
 
     // Apply a width to a <th> via a CSS custom property. The scoped stylesheet
     // reads --audit-col-width; absent it, the column falls back to auto.
+    //
+    // Known, intentional behaviour: during a live resize drag this updates the
+    // <th> width immediately, but the <td> body cells only catch up on the next
+    // .NET re-render (driven by OnColumnResized at pointer-up). The brief
+    // header/body width mismatch mid-drag is an accepted trade-off for an
+    // internal tool — not a bug.
     _applyWidth: function (th, widthPx) {
         th.style.setProperty("--audit-col-width", widthPx + "px");
     },