fix: GetTicketSummaries goes from 1 + N queries to 1 + 1

csharp/App/Backend/Controller.cs

@@ -2534,9 +2534,26 @@ public class Controller : ControllerBase
         if (user is null || user.UserType != 2) return Unauthorized();
 
         var tickets = Db.GetAllTickets();
+
+        var installationIds = tickets
+            .Where(t => t.InstallationId.HasValue)
+            .Select(t => t.InstallationId!.Value)
+            .Distinct()
+            .ToList();
+
+        var installationsById = installationIds.Count == 0
+            ? new Dictionary<Int64, Installation>()
+            : Db.Installations
+                .Where(i => installationIds.Contains(i.Id))
+                .ToList()
+                .ToDictionary(i => i.Id);
+
         var summaries = tickets.Select(t =>
         {
-            var installation = t.InstallationId.HasValue ? Db.GetInstallationById(t.InstallationId.Value) : null;
+            Installation? installation = null;
+            if (t.InstallationId.HasValue)
+                installationsById.TryGetValue(t.InstallationId.Value, out installation);
+
             return new
             {
                 t.Id, t.Subject, t.Status, t.Priority, t.Category, t.SubCategory,