knowledge(performance): add job queue reliability guidance

community/knowledge/performance/store-scheduled-task-id-to-avoid-duplicate-tasks.bad.al

@@ -0,0 +1,15 @@
+codeunit 50115 "Scheduled Task Duplicate Bad"
+{
+    procedure EnsureCleanupTask()
+    begin
+        // Every call creates another task for the same cleanup work.
+        TaskScheduler.CreateTask(Codeunit::"Scheduled Cleanup Work Bad", 0, true, CompanyName());
+    end;
+}
+
+codeunit 50116 "Scheduled Cleanup Work Bad"
+{
+    trigger OnRun()
+    begin
+    end;
+}