Weather Demo Update — New Icon Colorization Pipeline

[ldmcclatchey]

The weather demo has been updated with a new icon colorization pipeline.

• Icons now use a consistent palette generated by the recolor engine
• Improved contrast and theme alignment across all weather conditions
• Updated HTML/JS/CSS demo files under check_weather/web/
• Fixed browser caching issues for SVG assets
• Public demo now matches the development environment

This is a visual refinement, but it makes the demo feel much more polished and
provides a clearer example of how check_weather.py output can be rendered in a
browser.

Demo link: https://www.linktechengineering.net/weather_demo.html