fix(KB-186): add ID-based tiebreaker to sort comparators for stable ordering

- Add numeric ID tiebreaker to TaskStore.listTasks() when createdAt timestamps match
- Add same tiebreaker to InlineCreateCard and TaskDetailModal dependency dropdown sorts
- Add store-sort integration test verifying ascending ID order with identical timestamps
- Add InlineCreateCard tests for identical-timestamp dropdown ordering and search filtering
- Add TaskDetailModal test for identical-timestamp dependency dropdown ordering

packages/core/src/store.ts

@@ -249,7 +249,13 @@ export class TaskStore extends EventEmitter<TaskStoreEvents> {
       }
     }
 
-    return tasks.sort((a, b) => a.createdAt.localeCompare(b.createdAt));
+    return tasks.sort((a, b) => {
+      const cmp = a.createdAt.localeCompare(b.createdAt);
+      if (cmp !== 0) return cmp;
+      const aNum = parseInt(a.id.slice(a.id.lastIndexOf("-") + 1), 10) || 0;
+      const bNum = parseInt(b.id.slice(b.id.lastIndexOf("-") + 1), 10) || 0;
+      return aNum - bNum;
+    });
   }
 
   async moveTask(id: string, toColumn: Column): Promise<Task> {