🤖 fix: preserve killed status when onExit callback fires

The onExit callback was unconditionally setting status to 'exited',
overwriting the 'killed' status set by terminate(). Now guards with
if (process.status === 'running') to preserve killed/failed states.

Added test to verify killed status is preserved after termination.

Author: ethanndickson

src/node/services/backgroundProcessManager.test.ts

@@ -198,5 +198,24 @@ describe("BackgroundProcessManager", () => {
         expect(process?.stdoutBuffer.toArray()).toContain("test");
       }
     });
+
+    it("should preserve killed status after onExit callback fires", async () => {
+      // Spawn a long-running process
+      const result = await manager.spawn("workspace-1", "sleep 60", {
+        cwd: process.cwd(),
+      });
+
+      if (result.success) {
+        // Terminate it
+        await manager.terminate(result.processId);
+
+        // Wait for onExit callback to fire
+        await new Promise((resolve) => setTimeout(resolve, 100));
+
+        // Status should still be "killed", not "exited"
+        const proc = manager.getProcess(result.processId);
+        expect(proc?.status).toBe("killed");
+      }
+    });
   });
 });

src/node/services/backgroundProcessManager.ts

@@ -74,8 +74,11 @@ export class BackgroundProcessManager {
       onExit: (exitCode: number) => {
         log.debug(`Background process ${processId} exited with code ${exitCode}`);
         process.exitCode = exitCode;
-        process.exitTime = Date.now();
-        process.status = "exited";
+        process.exitTime ??= Date.now();
+        // Don't overwrite status if already marked as killed/failed by terminate()
+        if (process.status === "running") {
+          process.status = "exited";
+        }
       },
     });