etcp_connect + BGP_READY callbacks + router reconnect test

- etcp_connect.c: async connect API with EARLY/LATE/BGP_READY callbacks
- etcp_connect.h: declaration (via etcp_api.h)
- connect_deliver: fix to preserve unfired callback nodes
- etcp_set_routing_exchange_state: fires bgp_ready_cbk on TABLE_COMPLETE
- route_bgp: TABLE_COMPLETE handler + route_bgp_send_table_complete
- etcp.c: connections_count tracking, cleanup on close
- test_etcp_router_reconnect: a-b-c topology with b restart (etcp_connect)
- test_etcp_connect: unit tests for async connect API
- etcp_router: inflight/retrans/close improvements
- Various proxy/NAT/router cleanups

lib/debug_config.h

@@ -61,7 +61,8 @@ typedef int debug_category_t;
 #define DEBUG_CATEGORY_KEEPALIVE   21  // Link keepalive logic
 #define DEBUG_CATEGORY_ETCPROUTE   22  // ETCP routing
 #define DEBUG_CATEGORY_BBR         23  // BBR congestion control
-#define DEBUG_CATEGORY_COUNT       24  // Total number of categories
+#define DEBUG_CATEGORY_ETCP_DUMP   24  // ETCP packet dump
+#define DEBUG_CATEGORY_COUNT       25  // Total number of categories
 #define DEBUG_CATEGORY_ALL         (-1) // special value for all categories
 
 /* Debug configuration structure */
@@ -87,6 +88,7 @@ extern debug_config_t g_debug_config;
 void debug_config_init(void);
 
 /* Set debug level */
+// итоговый level = max (global level - здесь задается, category level)
 void debug_set_level(debug_level_t level);
 
 /* Set debug level for specific category (0 = disabled, otherwise uses that level) */