fix(uns): guard import save + comma-limitation hint + reset-on-open (review)

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/ImportEquipmentModal.razor

@@ -30,6 +30,7 @@
                     <textarea class="form-control form-control-sm mono" rows="12"
                               @bind="_csv" @bind:event="oninput" disabled="@_busy"
                               placeholder="Name,MachineCode,UnsLineId,DriverInstanceId,ZTag,SAPID,Manufacturer,Model&#10;mixer-01,MX_001,LINE-1,drv-modbus-01,ZT-12345,SAP-9876,Siemens,SIMATIC-1500"></textarea>
+                    <div class="form-text">Simple comma-separated values only — fields containing commas are not supported.</div>
 
                     @if (!string.IsNullOrWhiteSpace(_parseError))
                     {
@@ -91,16 +92,18 @@
     private bool _busy;
     private string? _parseError;
     private EquipmentImportResult? _result;
+    private bool _wasVisible;
 
     protected override void OnParametersSet()
     {
-        // Reset the working state each time the host (re)opens the modal.
-        if (!Visible)
+        // Reset only on the false→true transition so that re-renders while open don't wipe state.
+        if (Visible && !_wasVisible)
         {
             _csv = "";
             _parseError = null;
             _result = null;
         }
+        _wasVisible = Visible;
     }
 
     private async Task ImportAsync()
@@ -154,6 +157,7 @@
         var rows = new List<EquipmentInput>();
         for (var lineIdx = 1; lineIdx < lines.Length; lineIdx++)
         {
+            // NOTE: simple comma split — no RFC4180 quoting; values with commas are not supported.
             var parts = lines[lineIdx].Split(',').Select(c => c.Trim()).ToArray();
             if (parts.Length < RequiredColumns.Length)
             {

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/UnsTreeService.cs

@@ -575,7 +575,8 @@ public sealed class UnsTreeService(IDbContextFactory<OtOpcUaConfigDbContext> dbF
             inserted++;
         }
 
-        await db.SaveChangesAsync(ct);
+        if (inserted > 0)
+            await db.SaveChangesAsync(ct);
         return new EquipmentImportResult(inserted, skipped, errors);
     }