- Replace readline() with read(32) to avoid truncation at 0x0A bytes
- Add reset_input_buffer() to clear stale data before each read
- Add initial read to consume echo/acknowledgment from sensor
- Add frame header validation (0xFF 0x02) to reject invalid data
- Add delays to allow sensor response time
Fixes issue where NO2/H2S sensors showed random spikes due to
binary data containing newline characters being misinterpreted.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
