Odoo 19 does NOT use .o_dark class or data-bs-theme attribute. It sets
color-scheme via SCSS and stores preference in color_scheme cookie.
Added theme_detect.js that reads the cookie and sets data-woo-theme="dark"
on <html> for reliable CSS targeting. Fixed CSS dark mode selectors.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
