Adapt WSS to new boards and use MQTT domain for eSIM connectivity

Preserve main GNSS and volume behavior while porting verified TLS, receive fixes and full-handshake optimizations. Add MQTT connection diagnostics and route MQTT through banban.api.talkingq.com:1883.

Include migration documentation and regression tools. Firmware builds and package checks passed; user confirmed new-board connectivity after switching the MQTT host to the domain.

ql-application/threadx/interface/custom_app/inc/mqtt_connect_diag.h

@@ -0,0 +1,9 @@
+#ifndef TALKINGQ_MQTT_CONNECT_DIAG_H
+#define TALKINGQ_MQTT_CONNECT_DIAG_H
+
+#include "MQTTClient.h"
+
+/* Called by the single MQTT connection worker, before MQTTStartTask(). */
+int talkingq_mqtt_connect_diagnosed(MQTTClient *client, MQTTPacket_connectData *options);
+
+#endif

ql-application/threadx/interface/custom_app/inc/talkingq_wss.h

@@ -0,0 +1,20 @@
+#ifndef TALKINGQ_WSS_H
+#define TALKINGQ_WSS_H
+
+#include <stddef.h>
+
+#define TALKINGQ_WSS_URL "wss://banban.api.talkingq.com:443/ws"
+#define TALKINGQ_URL_CAPACITY 64
+#define TALKINGQ_HOST_CAPACITY 64
+#define TALKINGQ_PATH_CAPACITY 128
+
+extern const char talkingq_root_ca[];
+extern const size_t talkingq_root_ca_size;
+
+/* Reject cleartext, malformed authorities, invalid ports and oversized URLs. */
+int talkingq_parse_wss_url(const char *url, char *host, size_t host_size,
+                          int *port, char *path, size_t path_size);
+/* Only the former built-in endpoints migrate; custom WSS endpoints are kept. */
+int talkingq_is_legacy_ws_url(const char *url);
+
+#endif