fix: avoid duplicate orphaned subagent resumes

src/agents/subagent-orphan-recovery.test.ts

@@ -383,4 +383,37 @@ describe("subagent-orphan-recovery", () => {
     expect(result.skipped).toBe(1);
     expect(gateway.callGateway).toHaveBeenCalledOnce();
   });
+
+  it("does not retry a session after the gateway accepted resume but run remap failed", async () => {
+    vi.mocked(gateway.callGateway).mockResolvedValue({ runId: "new-run" } as never);
+    vi.mocked(subagentRegistry.replaceSubagentRunAfterSteer).mockReturnValue(false);
+
+    vi.mocked(sessions.loadSessionStore).mockReturnValue({
+      "agent:main:subagent:test-session-1": {
+        sessionId: "session-abc",
+        updatedAt: Date.now(),
+        abortedLastRun: true,
+      },
+    });
+
+    const activeRuns = new Map<string, SubagentRunRecord>();
+    activeRuns.set("run-1", createTestRunRecord());
+    const resumedSessionKeys = new Set<string>();
+
+    const first = await recoverOrphanedSubagentSessions({
+      getActiveRuns: () => activeRuns,
+      resumedSessionKeys,
+    });
+    const second = await recoverOrphanedSubagentSessions({
+      getActiveRuns: () => activeRuns,
+      resumedSessionKeys,
+    });
+
+    expect(first.recovered).toBe(1);
+    expect(first.failed).toBe(0);
+    expect(second.recovered).toBe(0);
+    expect(second.skipped).toBe(1);
+    expect(gateway.callGateway).toHaveBeenCalledOnce();
+    expect(sessions.updateSessionStore).toHaveBeenCalledOnce();
+  });
 });

src/agents/subagent-orphan-recovery.ts

@@ -108,9 +108,9 @@ async function resumeOrphanedSession(params: {
     });
     if (!remapped) {
       log.warn(
-        `resumed orphaned session ${params.sessionKey} but remap failed (old run already removed); treating as failure`,
+        `resumed orphaned session ${params.sessionKey} but remap failed (old run already removed); treating resume as accepted to avoid duplicate restarts`,
       );
-      return false;
+      return true;
     }
     log.info(`resumed orphaned session: ${params.sessionKey}`);
     return true;