radio: keep drain diagnostics at burst boundaries and test queued PCM

src/radio/radio_audio.c

@@ -640,8 +640,10 @@ void radio_audio_playback_progress(uint64_t group_id, uint64_t position, uint64_
             g_output_tracked = 1;
             if (g_output_voice_end > g_output_played && position >= g_output_voice_end) {
                 radio_audio_rx_guard(get_time_tb() + delay_tb + RADIO_VAD_BUSY_TB);
-                DEBUG_DEBUG(DEBUG_CATEGORY_VAD, "VAD output drained group=%016llx position=%llu delay=%.1fms guard=200ms",
-                            (unsigned long long)group_id, (unsigned long long)position, delay_tb / 10.0);
+                int sources = 0;
+                for (int i = 0; i < RADIO_AUDIO_MAX_SOURCES; ++i) sources += g_sources[i].used != 0;
+                if (!sources) DEBUG_DEBUG(DEBUG_CATEGORY_VAD, "VAD output drained group=%016llx position=%llu delay=%.1fms guard=200ms",
+                                          (unsigned long long)group_id, (unsigned long long)position, delay_tb / 10.0);
             }
             g_output_played = position;
         }
@@ -924,7 +926,6 @@ static void radio_audio_vad_sample(const int16_t* frame) {
     pthread_mutex_lock(&g_mtx);
     g_vad_win_len = 0;
     uint64_t now = get_time_tb();
-    if (radio_audio_vad_block(now)) return; /* RX мог начаться, пока Silero работал без общего mutex. */
     uint64_t inference_tb = now - started;
     uint64_t gap_tb = g_vad_diag.last_window_tb ? now - g_vad_diag.last_window_tb : 0;
     g_vad_diag.last_window_tb = now;
@@ -937,6 +938,7 @@ static void radio_audio_vad_sample(const int16_t* frame) {
         DEBUG_ERROR(DEBUG_CATEGORY_VAD, "VAD inference failed group=%016llx window=%llu rc=%d inference=%.1fms",
                     (unsigned long long)g_group_id, (unsigned long long)g_vad_diag.total_windows, result, inference_tb / 10.0);
     }
+    if (radio_audio_vad_block(now)) return; /* RX мог начаться, пока Silero работал без общего mutex. */
     struct radio_vad_fsm before = g_vad_fsm;
     int busy = 0;
     int64_t rx_age_ms = g_last_rx_tb ? (int64_t)((now - g_last_rx_tb) / 10) : -1;