[mqtt] Replace sprintf with snprintf for friendly name hash

esphome/__main__.py

@@ -222,8 +222,13 @@ def choose_upload_log_host(
             else:
                 resolved.append(device)
         if not resolved:
+            if CORE.dashboard:
+                hint = "If you know the IP, set 'use_address' in your network config."
+            else:
+                hint = "If you know the IP, try --device <IP>"
             raise EsphomeError(
-                f"All specified devices {defaults} could not be resolved. Is the device connected to the network?"
+                f"All specified devices {defaults} could not be resolved. "
+                f"Is the device connected to the network? {hint}"
             )
         return resolved
 

esphome/components/mqtt/mqtt_component.cpp

@@ -189,8 +189,7 @@ bool MQTTComponent::send_discovery_() {
         StringRef object_id = this->get_default_object_id_to_(object_id_buf);
         if (discovery_info.unique_id_generator == MQTT_MAC_ADDRESS_UNIQUE_ID_GENERATOR) {
           char friendly_name_hash[9];
-          sprintf(friendly_name_hash, "%08" PRIx32, fnv1_hash(this->friendly_name_()));
-          friendly_name_hash[8] = 0;  // ensure the hash-string ends with null
+          snprintf(friendly_name_hash, sizeof(friendly_name_hash), "%08" PRIx32, fnv1_hash(this->friendly_name_()));
           // Format: mac-component_type-hash (e.g. "aabbccddeeff-sensor-12345678")
           // MAC (12) + "-" (1) + domain (max 20) + "-" (1) + hash (8) + null (1) = 43
           char unique_id[MAC_ADDRESS_BUFFER_SIZE + ESPHOME_DOMAIN_MAX_LEN + 11];

esphome/espota2.py

@@ -400,6 +400,8 @@ def run_ota_impl_(
             "Error resolving IP address of %s. Is it connected to WiFi?",
             remote_host,
         )
+        if not CORE.dashboard:
+            _LOGGER.error("(If you know the IP, try --device <IP>)")
         _LOGGER.error(
             "(If this error persists, please set a static IP address: "
             "https://esphome.io/components/wifi/#manual-ips)"