Refactor client version string generation in MQTTBridge

src/helpers/bridges/MQTTBridge.cpp

@@ -684,7 +684,7 @@ bool MQTTBridge::publishStatus() {
   
   // Build client version string
   char client_version[64];
-  snprintf(client_version, sizeof(client_version), "meshcore/%s", _firmware_version);
+  getClientVersion(client_version, sizeof(client_version));
   
   // Collect stats on-demand if sources are available
   int battery_mv = -1;
@@ -1110,7 +1110,7 @@ bool MQTTBridge::createAuthToken() {
   
   // Build client version string (same format as used in status messages)
   char client_version[64];
-  snprintf(client_version, sizeof(client_version), "meshcore/%s", _firmware_version);
+  getClientVersion(client_version, sizeof(client_version));
   
   // Get email from preferences (if set)
   const char* email = nullptr;
@@ -1374,7 +1374,7 @@ void MQTTBridge::publishStatusToAnalyzerClient(PsychicMqttClient* client, const
   
   // Build client version string
   char client_version[64];
-  snprintf(client_version, sizeof(client_version), "meshcore/%s", _firmware_version);
+  getClientVersion(client_version, sizeof(client_version));
   
   // Collect stats on-demand if sources are available
   int battery_mv = -1;
@@ -1488,7 +1488,7 @@ void MQTTBridge::maintainAnalyzerConnections() {
       
       // Build client version string (same format as used in status messages)
       char client_version[64];
-      snprintf(client_version, sizeof(client_version), "meshcore/%s", _firmware_version);
+      getClientVersion(client_version, sizeof(client_version));
       
       // Get email from preferences (if set)
       const char* email = nullptr;
@@ -1577,9 +1577,9 @@ void MQTTBridge::maintainAnalyzerConnections() {
         owner_key = owner_key_uppercase;
       }
       
-      // Build client version string (same format as used in status messages)
+      // Build client version string
       char client_version[64];
-      snprintf(client_version, sizeof(client_version), "meshcore/%s", _firmware_version);
+      getClientVersion(client_version, sizeof(client_version));
       
       // Get email from preferences (if set)
       const char* email = nullptr;
@@ -1878,6 +1878,14 @@ Timezone* MQTTBridge::createTimezoneFromString(const char* tz_string) {
   }
 }
 
+void MQTTBridge::getClientVersion(char* buffer, size_t buffer_size) const {
+  if (!buffer || buffer_size == 0) {
+    return;
+  }
+  // Generate client version string in format "meshcore/{firmware_version}"
+  snprintf(buffer, buffer_size, "meshcore/%s", _firmware_version);
+}
+
 void MQTTBridge::logMemoryStatus() {
   MQTT_DEBUG_PRINTLN("=== Memory Status ===");
   MQTT_DEBUG_PRINTLN("Free heap: %d bytes", ESP.getFreeHeap());

src/helpers/bridges/MQTTBridge.h

@@ -362,6 +362,15 @@ public:
                        mesh::MainBoard* board, mesh::MillisecondClock* ms);
 
 private:
+  /**
+   * Generate client version string in format "meshcore/{firmware_version}"
+   * Memory-efficient: writes to provided buffer, no dynamic allocation
+   *
+   * @param buffer Buffer to write the client version string to
+   * @param buffer_size Size of the buffer (must be at least 64 bytes)
+   */
+  void getClientVersion(char* buffer, size_t buffer_size) const;
+
   /**
    * Log memory status for debugging
    */