fix(daemon): handle startup stderr errors

src/main/daemon/daemon-child-exit-observer.test.ts

@@ -86,6 +86,16 @@ describe('observeDaemonChildExit', () => {
     expect(onExit).toHaveBeenCalledOnce()
   })
 
+  it('swallows stderr errors before readiness', () => {
+    const child = createChild()
+    const onExit = vi.fn()
+    const observer = observeDaemonChildExit(child, onExit)
+
+    expect(() => child.stderr.emit('error', new Error('startup pipe error'))).not.toThrow()
+    expect(onExit).not.toHaveBeenCalled()
+    observer.stop()
+  })
+
   it('does not infer an exit from stderr or contact loss', () => {
     const child = createChild()
     const onExit = vi.fn()

src/main/daemon/daemon-child-exit-observer.ts

@@ -101,6 +101,7 @@ export function observeDaemonChildExit(
   }
 
   child.stderr?.on('data', onStderr)
+  child.stderr?.on('error', onStderrError)
   child.stderr?.on('end', onStderrEnd)
   child.stderr?.on('close', onStderrEnd)
 
@@ -113,7 +114,6 @@ export function observeDaemonChildExit(
         return
       }
       ready = true
-      child.stderr?.on('error', onStderrError)
       child.stderr?.unref?.()
       child.on('exit', onProcessExit)
     },