esphome regression compile errors

[boverby]

existing master fails under newer versions of esphome, sample regression results:

pip3 install esphome==2024.10.3

• works with modified microfire libraries (comment out Wifi.h like keyser75000 fork and PlatformIO Core, version 6.1.15
• I am still rummaging thru change logs to see when this flopped

pip3 install esphome==2025.8.4

• works with modified microfire libraries (comment out Wifi.h like keyser75000 fork and PlatformIO Core, version 6.1.15

pip3 install esphome==2025.9.1

• fails with
  src/esphome/components/now_mqtt/now_mqtt.cpp:196:67: error: request for member 'c_str' in 'esphome::sensor::state_class_to_string(((int)obj->esphome::sensor::Sensor::get_state_class()))', which is of pointer type 'const esphome::LogString*' (maybe you meant to use '->' ?) 196 | line += state_class_to_string(obj->get_state_class()).c_str(); | ^~~~~ *** [.pioenvs/now29/src/esphome/components/now_mqtt/now_mqtt.cpp.o] Error 1
• I suspect [sensor] Change state_class_to_string() to return const char* to avoid allocations