fix(server): keep follow-up tasks pending until nested work finishes

apps/server/src/mcp/OrchestratorMcpService.test.ts

@@ -78,8 +78,13 @@ const layerOrchestratorService = OrchestratorMcpService.layer.pipe(
 );
 
 describe("OrchestratorMcpService", () => {
-  it.effect("retries terminal acknowledgement with a fresh command id", () =>
+  const acknowledgementTest =
+    "retries terminal acknowledgement with a fresh command id (follow-up: %s)";
+  const cases = [false, true, "never-started", "queued"] as const;
+  it.effect.each(cases)(acknowledgementTest, (followup) =>
     Effect.gen(function* () {
+      const failedBeforeStart = followup === "never-started";
+      const queued = followup === "queued";
       const parentThreadId = ThreadId.make("thread:mcp-ack-parent");
       const childThreadId = ThreadId.make("thread:mcp-ack-child");
       const childRunId = RunId.make("run:mcp-ack-child");
@@ -107,7 +112,7 @@ describe("OrchestratorMcpService", () => {
             childThreadId,
             driver: "codex",
             model: "gpt-5.6-terra",
-            result: "terminal result",
+            result: failedBeforeStart || queued ? null : "terminal result",
             completionDelivery: { state: "pending" },
           },
         ],
@@ -117,9 +122,13 @@ describe("OrchestratorMcpService", () => {
         runs: [
           {
             id: childRunId,
+            ...(followup ? { delegatedTaskId: taskId } : {}),
             ordinal: 1,
             status: "completed",
             startedAt: DateTime.makeUnsafe("2026-10-03T10:00:00Z"),
+            ...(failedBeforeStart || queued
+              ? { ordinal: 3, status: failedBeforeStart ? "failed" : "queued", startedAt: null }
+              : {}),
             completedAt: DateTime.makeUnsafe("2026-10-03T10:10:00Z"),
           },
           {
@@ -146,7 +155,7 @@ describe("OrchestratorMcpService", () => {
         providerThreads: [],
         runtimeRequests: [],
       } as unknown as OrchestrationV2ThreadProjection;
-      let hasNestedWork = true;
+      let hasNestedWork = !failedBeforeStart && !queued;
       let settleAfterTaskRead = false;
       const layerDependencies = Layer.mergeAll(
         NodeServices.layer,
@@ -159,7 +168,11 @@ describe("OrchestratorMcpService", () => {
                   ? {
                       ...childProjection,
                       subagents: [
-                        { ...parentProjection.subagents[0]!, status: "running" as const },
+                        {
+                          ...parentProjection.subagents[0]!,
+                          runId: childRunId,
+                          status: "running" as const,
+                        },
                       ],
                     }
                   : childProjection;
@@ -189,7 +202,7 @@ describe("OrchestratorMcpService", () => {
             ]).pipe(
               Effect.andThen(Ref.updateAndGet(acknowledgementAttempts, (count) => count + 1)),
               Effect.flatMap((attempt) =>
-                attempt === 1
+                attempt === 1 && !hasNestedWork
                   ? Effect.fail(new Error("simulated acknowledgement failure") as never)
                   : Effect.succeed({} as never),
               ),
@@ -220,20 +233,35 @@ describe("OrchestratorMcpService", () => {
 
       yield* Effect.gen(function* () {
         const service = yield* OrchestratorMcpService.OrchestratorMcpService;
-        const pending = yield* service.taskStatus(scope, taskId);
-        assert.equal(pending.status, "running");
-        assert.equal(pending.workState, "waiting_for_children");
-        assert.isNull(pending.summary);
-        assert.isNull(pending.resultContextTransferId);
-        assert.equal(yield* Ref.get(acknowledgementAttempts), 0);
-        hasNestedWork = false;
+        if (queued) {
+          const pending = yield* service.taskStatus(scope, taskId);
+          assert.equal(pending.status, "queued");
+          assert.equal(pending.workState, "working");
+          return;
+        }
+        if (!failedBeforeStart) {
+          const pending = yield* service.taskStatus(scope, taskId);
+          assert.equal(pending.status, "running");
+          assert.equal(pending.workState, "waiting_for_children");
+          assert.isNull(pending.summary);
+          assert.isNull(pending.resultContextTransferId);
+          assert.equal(yield* Ref.get(acknowledgementAttempts), 0);
+          hasNestedWork = false;
+        }
         const error = yield* service.taskStatus(scope, taskId).pipe(Effect.flip);
         assert.equal(error.code, "orchestration_error");
 
-        // Completion lands after task selection, before the remaining parent/child reads.
-        hasNestedWork = true;
-        settleAfterTaskRead = true;
+        if (!failedBeforeStart) {
+          // Completion lands after task selection, before the remaining parent/child reads.
+          hasNestedWork = true;
+          settleAfterTaskRead = true;
+        }
         const result = yield* service.taskStatus(scope, taskId);
+        if (failedBeforeStart) {
+          assert.equal(result.status, "failed");
+          assert.equal(result.workState, "result_available");
+          return;
+        }
         assert.equal(result.status, "completed");
         assert.equal(result.summary, "terminal result");
         assert.equal(result.latestTerminalRunId, childRunId);

apps/server/src/mcp/OrchestratorMcpService.ts

@@ -96,7 +96,7 @@ import type {
   ProjectionRecordField,
   ProjectionRecordFilter,
 } from "../orchestration-v2/ProjectionStore.ts";
-import { runOutcome } from "../orchestration-v2/RestartBackgroundNote.ts";
+import { neverStarted, runOutcome } from "../orchestration-v2/RestartBackgroundNote.ts";
 import * as ThreadManagementService from "../orchestration-v2/ThreadManagementService.ts";
 import * as ThreadLaunchService from "../orchestration-v2/ThreadLaunchService.ts";
 import * as GitVcsDriver from "../vcs/GitVcsDriver.ts";
@@ -1518,11 +1518,20 @@ const make = Effect.gen(function* () {
             .filter((run) => run.delegatedTaskId === task.id)
             .toSorted((a, b) => b.ordinal - a.ordinal)[0]
         : progress.resultRun;
+    const taskRuns = childControls.runs.filter((run) => run.delegatedTaskId === task.id);
     const taskWorkState =
       childRun?.delegatedTaskId === task.id
-        ? isTerminalTaskStatus(taskStatusForRun(taskResultRun))
+        ? taskResultRun !== undefined &&
+          isTerminalTaskStatus(taskStatusForRun(taskResultRun)) &&
+          taskRuns.every(neverStarted)
           ? "result_available"
-          : "working"
+          : delegatedTaskProgress({
+              ...childControls,
+              runs: taskRuns,
+              subagents: childControls.subagents.filter((subagent) =>
+                taskRuns.some((run) => run.id === subagent.runId),
+              ),
+            }).state
         : progress.state;
     const resultRunIds = [
       ...new Set(