Adds a "CSS Variables" panel to the Styling tab with a color picker and
description for every color token in globals.css (base, sidebar, design
token aliases, event colors, all-day chips), plus a "Custom CSS" textarea
that loads after the default stylesheet and can override any rule.
Overrides are stored per-user (customCssVars, customCss) and applied on
the root container's inline style, so they take precedence over themes
and per-field settings.
v1.113.0
mARTin-B78
02b2e40649