fix(adminui): alias update pins invariants + LoadAliasTagAsync + null-driver guard (review)

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

@@ -204,6 +204,16 @@ public sealed class UnsTreeService(IDbContextFactory<OtOpcUaConfigDbContext> dbF
             .FirstOrDefaultAsync(ct);
     }
 
+    /// <inheritdoc />
+    public async Task<AliasTagEditDto?> LoadAliasTagAsync(string tagId, CancellationToken ct = default)
+    {
+        await using var db = await dbFactory.CreateDbContextAsync(ct);
+        var t = await db.Tags.AsNoTracking().FirstOrDefaultAsync(x => x.TagId == tagId, ct);
+        if (t is null) return null;
+        return new AliasTagEditDto(t.TagId, t.Name, t.DriverInstanceId, t.DataType, t.AccessLevel,
+            ExtractTagConfigFullName(t.TagConfig) ?? string.Empty, t.RowVersion);
+    }
+
     /// <inheritdoc />
     public async Task<VirtualTagEditDto?> LoadVirtualTagAsync(string virtualTagId, CancellationToken ct = default)
     {
@@ -975,6 +985,8 @@ public sealed class UnsTreeService(IDbContextFactory<OtOpcUaConfigDbContext> dbF
         entity.DataType = input.DataType;
         entity.AccessLevel = input.AccessLevel;
         entity.FolderPath = null;
+        entity.WriteIdempotent = false;
+        entity.PollGroupId = null;
         entity.TagConfig = BuildAliasTagConfig(input.FullName);
 
         try
@@ -1397,6 +1409,9 @@ public sealed class UnsTreeService(IDbContextFactory<OtOpcUaConfigDbContext> dbF
         string? equipmentCluster,
         CancellationToken ct)
     {
+        if (string.IsNullOrWhiteSpace(driverInstanceId))
+            return new UnsMutationResult(false, "An alias must be bound to a Galaxy gateway.");
+
         var driver = await db.DriverInstances.FirstOrDefaultAsync(d => d.DriverInstanceId == driverInstanceId, ct);
         if (driver is null)
         {