Flatten so the repo root is the Arduino sketchbook; the project lives in
WeatherPredictor/. Add a collection index README at the root and move the
detailed project README into WeatherPredictor/.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Record each forecast change (Zambretti letter transition) with a
timestamp into a 24-entry ring buffer, persisted to LittleFS and
restored on boot. New /api/forecasts endpoint and a 'Forecast log'
panel in the web UI (newest first, category colour, timestamp).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>