Adds a small weather icon in the header, right where the old camera
button used to be. Shows current conditions (sun, cloud,
sun-behind-cloud, rain, snow, thunderstorm) for whichever location is
currently active, including active location presets, so switching to
e.g. Milan shows Milan's weather. Powered by the free Open-Meteo API
(no API key needed), refreshed automatically every 10 minutes in the
background, or immediately after switching to a different location
preset. Icons are drawn entirely with TFT_eSPI basic shapes (circles,
lines), no image files or extra fonts needed.
The initial implementation failed to parse Open-Meteo's response
(ArduinoJson "InvalidInput") because the API replies with
Transfer-Encoding: chunked and streaming directly from
http.getStream() didn't reassemble the chunks correctly. Fixed by
collecting the full body via http.getString() first, then parsing
that.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
