Fix X-ASR release tail capture

Ariver

2026-06-14 d14fa75079de570cb9c4dbf63f6b5bd65f959b09

 privatevoice.src/internal/engine/engine_darwin_test.go

@@ -6,6 +6,7 @@
   "os"
   "path/filepath"
   "testing"
   "time"

   "voicesnap/internal/model"
)
@@ -163,6 +164,19 @@
   }
}

func TestXASRRequestsReleaseTailCaptureDelay(t *testing.T) {
   got := (&xasrStreamingEngine{}).ReleaseTailCaptureDelay()
   if got != 300*time.Millisecond {
      t.Fatalf("ReleaseTailCaptureDelay() = %v, want 300ms", got)
   }
}

func TestOfflineSherpaDoesNotRequestReleaseTailCapture(t *testing.T) {
   if _, ok := any(&sherpaEngine{}).(ReleaseTailCaptureEngine); ok {
      t.Fatal("offline sherpa engine should not request release tail capture")
   }
}

func TestXASRRealModelSmoke(t *testing.T) {
   if os.Getenv("PRIVATEVOICE_XASR_SMOKE") != "1" {
      t.Skip("set PRIVATEVOICE_XASR_SMOKE=1 to run the real X-ASR model smoke test")