Improve the mqttSubstituteTopic function to ensure that it reports
overflow when the output buffer is full, preventing silent truncation
of topics. Update related tests to verify the new behavior for
literal overflow and exact fit scenarios, enhancing robustness and
correctness of topic handling.
Include detailed instructions for local testing of observer and WiFi
functionality without hardware. Document the use of a mock backend and
Wokwi ESP32-S3 simulation for easier development and testing.
Enhance the MQTT implementation documentation to improve developer
experience and facilitate testing workflows.
agessaman