Add historical weather min/max values and occurrence years

[mot-yelraf]

Summary

The Caelus historical weather section now shows Min and Max with occurrence years, followed by Avg, for temperature, RH, wind, and rainfall. The heading uses “Historical Min, Max, Avg 1991–2026 for 19-Sep” format to match the supplied reference.

Daily lows/highs supply temperature, RH, and wind extrema; daily totals supply rainfall extrema. Ties show the earliest year. Existing averages-only caches rebuild automatically, while average fields remain compatible. Updated the user guide and version to v0.26.262.1.

Verification

• macOS, Python 3.13.9; isolated host fixture, mocked weather archive, no MQTT broker or direct hardware required.
• python3 -m pytest testApparatus/test_weather_climate.py testApparatus/test_rain_climate.py -q: 26 passed.
• python3 -m pytest testApparatus/test_integrated_weather_forecast.py testApparatus/test_weather_forecast.py -q: 82 passed.
• npm run validate:pr: 42 Chromium tests passed, including Metric/Imperial and desktop/tablet/mobile layout checks.
• Reviewed rendered screenshots and received user verification.
• git diff --check: passed.

Contributor checklist

• This pull request is focused on one logical change.
• I added or updated tests for behavior changes.
• I updated the canonical documentation when behavior or configuration changed.
• I did not commit credentials, private runtime configuration, databases, or logs.
• I preserved compatibility-sensitive MQTT, settings, switch identity, and persistence behavior, or documented an intentional break.

Maintainer verification

• Required remote checks pass (Python 3.11/3.13 compile and full regression suite with coverage floor).
• npm run validate:pr passes on a trusted host when the change can affect rendered UI behavior.
• Hardware-, broker-, onboarding-, and platform-specific behavior not covered remotely is recorded below.

Residual risk or unverified areas

Live archive retrieval was mocked in automated tests. No hardware, MQTT broker, onboarding, or non-macOS runtime testing was needed for this weather display change.