Bump firmware version to v1.10.3 (#351)

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: k9ert

boot/main/boot.py

@@ -13,7 +13,7 @@
 pwr = pyb.Pin("B15", pyb.Pin.OUT)
 pwr.on()
 
-version = "<version:tag10>0101000199</version:tag10>"
+version = "<version:tag10>0101000399</version:tag10>"
 
 # get i2c
 i2c = pyb.I2C(1)