#9 Issue 9: [Integration] Weather API

[elizabetheonoja-art]

Description:
Correlate energy usage with temperature. Fetch local weather data to overlay on usage charts.

Acceptance Criteria:

[ ] OpenWeatherMap API integration.

[ ] Store temp_c alongside usage logs in DB.

[ ] Allow querying usage by temperature range.

Priority: Low
Labels: data-science, external-api