Add local UDP discovery and invitation delivery for chat clients

lib/debug_config.c

@@ -137,6 +137,7 @@ static const struct {
     {"vad", DEBUG_CATEGORY_VAD},
     {"aec", DEBUG_CATEGORY_AEC},
     {"stream", DEBUG_CATEGORY_STREAM},
+    {"discovery", DEBUG_CATEGORY_DISCOVERY},
     {"all", DEBUG_CATEGORY_ALL},
     {NULL, DEBUG_CATEGORY_NONE}
 };

lib/debug_config.h

@@ -75,7 +75,8 @@ typedef int debug_category_t;
 #define DEBUG_CATEGORY_VAD        34  // VAD — Silero voice activity detector (ONNX Runtime)
 #define DEBUG_CATEGORY_AEC        35  // AEC — acoustic echo cancellation (SpeexDSP)
 #define DEBUG_CATEGORY_STREAM     36  // Подписанные потоки, FEC, буферы и выбор поставщиков
-#define DEBUG_CATEGORY_COUNT      37  // Total number of categories
+#define DEBUG_CATEGORY_DISCOVERY   37  // LAN UDP: discovery and delivery
+#define DEBUG_CATEGORY_COUNT      38  // Total number of categories
 #define DEBUG_CATEGORY_ALL         (-1) // special value for all categories
 
 /* Debug configuration structure */