feat: BMP180 read and sea-level pressure conversion

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

WeatherPredictor/sensors.h

@@ -0,0 +1,7 @@
+#pragma once
+#include <Arduino.h>
+
+bool  sensorsBegin();
+float readAbsPressureHpa();                          // absolute (station) pressure, hPa
+float readTemperatureC();                            // degrees C
+float toSeaLevelHpa(float absHpa, float altitudeM);  // mean-sea-level pressure, hPa