test(FN-5135): lock deletedAt SSE payload contract

Fusion-Task-Id: FN-5135
Fusion-Task-Lineage: 182c496e-4e3a-4353-be53-86dd4cc5ba19

packages/dashboard/app/hooks/__tests__/useTasks.test.ts

@@ -1262,7 +1262,7 @@ describe("useTasks", () => {
 
       const { result } = renderHook(() => useTasks({ projectId: "proj-1" }));
 
-      expect(result.current.tasks.map((task) => task.id)).toEqual(["FN-AAA", "FN-DELETED"]);
+      expect(result.current.tasks.map((task) => task.id)).toEqual(["FN-AAA"]);
     });
   });
 

packages/dashboard/src/__tests__/sse-task-deleted-payload.test.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it } from "vitest";
+import { stripTaskListHeavyFields } from "../sse";
+
+describe("stripTaskListHeavyFields", () => {
+  it("preserves deletedAt on slim SSE payloads", () => {
+    const payload = {
+      id: "FN-123",
+      title: "soft deleted task",
+      deletedAt: "2026-05-19T00:00:00.000Z",
+      log: [{ action: "[timing] step in 5ms" }],
+    };
+
+    const slimmed = stripTaskListHeavyFields(payload);
+
+    expect(slimmed.deletedAt).toBe("2026-05-19T00:00:00.000Z");
+  });
+});

packages/dashboard/src/sse.ts

@@ -134,7 +134,7 @@ function safeWrite(res: Response, data: string): SafeWriteResult {
   }
 }
 
-function stripTaskListHeavyFields<T>(task: T): T {
+export function stripTaskListHeavyFields<T>(task: T): T {
   if (!task || typeof task !== "object" || Array.isArray(task)) {
     return task;
   }
@@ -156,7 +156,14 @@ function stripTaskListHeavyFields<T>(task: T): T {
       ? existingTimed
       : sumTimedLogEntries(candidate.log);
 
-  return { ...task, log: [], timedExecutionMs, tokenUsage: candidate.tokenUsage, workflowStepResults: candidate.workflowStepResults } as T;
+  return {
+    ...task,
+    // FN-5105/FN-5135: preserve deletedAt in SSE slim payloads for soft-delete suppression.
+    log: [],
+    timedExecutionMs,
+    tokenUsage: candidate.tokenUsage,
+    workflowStepResults: candidate.workflowStepResults,
+  } as T;
 }
 
 function sumTimedLogEntries(log: unknown): number {