Route WFM stereo through explicit hybrid GPU/CPU demod path

internal/recorder/demod.go

@@ -69,7 +69,11 @@ func (m *Manager) demodAndWrite(dir string, ev detector.Event, iq []complex64, f
 		}
 	}
 	if audio == nil {
-		log.Printf("gpudemod: CPU demod fallback used for event %d (%s)", ev.ID, name)
+		if name == "WFM_STEREO" {
+			log.Printf("gpudemod: WFM_STEREO using CPU stereo/RDS post-process for event %d", ev.ID)
+		} else {
+			log.Printf("gpudemod: CPU demod fallback used for event %d (%s)", ev.ID, name)
+		}
 		shifted := dsp.FreqShift(iq, m.sampleRate, offset)
 		cutoff := bw / 2
 		if cutoff < 200 {

internal/recorder/demod_helpers.go

@@ -0,0 +1,22 @@
+package recorder
+
+import "sdr-visual-suite/internal/demod/gpudemod"
+
+func gpuModeFor(name string) (gpudemod.DemodType, bool) {
+	switch name {
+	case "NFM":
+		return gpudemod.DemodNFM, true
+	case "WFM", "WFM_STEREO":
+		return gpudemod.DemodWFM, true
+	case "AM":
+		return gpudemod.DemodAM, true
+	case "USB":
+		return gpudemod.DemodUSB, true
+	case "LSB":
+		return gpudemod.DemodLSB, true
+	case "CW":
+		return gpudemod.DemodCW, true
+	default:
+		return 0, false
+	}
+}

internal/recorder/demod_live.go

@@ -82,7 +82,11 @@ func (m *Manager) DemodLive(centerHz float64, bw float64, mode string, seconds i
 		}
 	}
 	if audio == nil {
-		log.Printf("gpudemod: CPU live demod fallback used (%s)", name)
+		if name == "WFM_STEREO" {
+			log.Printf("gpudemod: WFM_STEREO live path using CPU stereo/RDS post-process")
+		} else {
+			log.Printf("gpudemod: CPU live demod fallback used (%s)", name)
+		}
 		shifted := dsp.FreqShift(segment, m.sampleRate, offset)
 		cutoff := bw / 2
 		if cutoff < 200 {