fix(codex): settle closed children independently of prior errors

Codex derives a close record's status from the child's previous state,
so closing an errored child produces a failed record even after shutdown.
Treat close as a terminal-preserving child event rather than a successful
control-card status, retaining earlier completion when a close is stale.

packages/server/src/server/agent/providers/codex-app-server-agent.ts

@@ -1864,7 +1864,7 @@ function readCodexSubAgentActivity(item: unknown): CodexSubAgentActivity | null
 interface CodexCollabAgentUpdate {
   threadId: string;
   status: ToolCallTimelineItem["status"];
-  shutdown: boolean;
+  preservesTerminal: boolean;
   reopen: boolean;
 }
 
@@ -1891,11 +1891,8 @@ function readCodexCollabAgentControl(item: unknown): CodexCollabAgentControl | n
       return [
         {
           threadId,
-          status:
-            record.tool === "closeAgent" && record.status === "completed" && status === "running"
-              ? "canceled"
-              : status,
-          shutdown: state.status === "shutdown",
+          status: record.tool === "closeAgent" && status === "running" ? "canceled" : status,
+          preservesTerminal: state.status === "shutdown" || record.tool === "closeAgent",
           reopen: record.tool === "sendInput" && record.status === "completed",
         },
       ];
@@ -1916,7 +1913,7 @@ function resolveCodexCollabAgentUpdate(
 ): ToolCallTimelineItem["status"] {
   if (
     isTerminalSubAgentStatus(previous) &&
-    (update.shutdown || (update.status === "running" && !update.reopen))
+    (update.preservesTerminal || (update.status === "running" && !update.reopen))
   ) {
     return previous;
   }

packages/server/src/server/agent/providers/codex/collab-replay.test.ts

@@ -86,6 +86,35 @@ describe("Codex collaboration history", () => {
     ).toEqual([{ id: "first", status: "canceled" }]);
   });
 
+  test("stops counting an errored child whose close record reports failed", async () => {
+    const history = await replay([
+      collab("spawnAgent", { first: "pendingInit" }, "spawn-first"),
+      { ...collab("closeAgent", { first: "errored" }), status: "failed" },
+    ]);
+    expect(
+      history.flatMap((event) =>
+        event.type === "provider_subagent" && event.event.type === "upsert"
+          ? [{ id: event.event.id, status: event.event.status }]
+          : [],
+      ),
+    ).toEqual([{ id: "first", status: "canceled" }]);
+  });
+
+  test("preserves completion when a close carries an older running snapshot", async () => {
+    const history = await replay([
+      collab("spawnAgent", { first: "pendingInit" }, "spawn-first"),
+      collab("wait", { first: "completed" }),
+      collab("closeAgent", { first: "running" }),
+    ]);
+    expect(
+      history.flatMap((event) =>
+        event.type === "provider_subagent" && event.event.type === "upsert"
+          ? [{ id: event.event.id, status: event.event.status }]
+          : [],
+      ),
+    ).toEqual([{ id: "first", status: "completed" }]);
+  });
+
   test.each([
     ["shutdown", "canceled"],
     ["notFound", "failed"],