Add slow recognition diagnostics

Ariver

2026-07-01 2547282e0942a09b67fccfd53cf62a403ccd4a52

 privatevoice.src/internal/engine/engine_darwin_test.go

@@ -187,15 +187,32 @@
   }
}

func TestXASREnablesHoldPreCapture(t *testing.T) {
   if !(&xasrStreamingEngine{}).HoldPreCaptureEnabled() {
      t.Fatal("X-ASR should enable hold pre-capture")
func TestSenseVoiceRequestsReleaseTailCaptureDelay(t *testing.T) {
   got := (&sherpaEngine{backendKind: model.BackendSenseVoice}).ReleaseTailCaptureDelay()
   if got != 100*time.Millisecond {
      t.Fatalf("ReleaseTailCaptureDelay() = %v, want 100ms", got)
   }
}

func TestOfflineSherpaDoesNotRequestReleaseTailCapture(t *testing.T) {
   if _, ok := any(&sherpaEngine{}).(ReleaseTailCaptureEngine); ok {
      t.Fatal("offline sherpa engine should not request release tail capture")
func TestOtherSherpaModelsDoNotRequestReleaseTailCaptureDelay(t *testing.T) {
   for _, backendKind := range []string{
      model.BackendMoonshine,
      model.BackendTransducer,
      model.BackendNemoTransducer,
      model.BackendQwen3ASR,
   } {
      t.Run(backendKind, func(t *testing.T) {
         got := (&sherpaEngine{backendKind: backendKind}).ReleaseTailCaptureDelay()
         if got != 0 {
            t.Fatalf("ReleaseTailCaptureDelay() = %v, want 0", got)
         }
      })
   }
}

func TestXASREnablesHoldPreCapture(t *testing.T) {
   if !(&xasrStreamingEngine{}).HoldPreCaptureEnabled() {
      t.Fatal("X-ASR should enable hold pre-capture")
   }
}