dashboard.css used var(--surface0/1/2) and var(--text) throughout the
agent context menu, tabbar overflow dropdown, and logs toolbar — none
of which are declared in base.css (the palette only defines --bg-elev,
--border, --purple-dim, --fg etc). This caused all three dropdowns to
render with a transparent background (issue #996).
Replacements:
--surface0 → --bg-elev (dropdown background)
--surface1 → --border (hover / active state)
--surface2 → --purple-dim (border / separator)
--text → --fg (label colour)
Also addresses two argus yellows from the PR #997 review:
- Skip updateTabbarOverflow() early when the dropdown is open; avoids
DOM flicker from the 1s badge-update tick while the menu is visible.
- Fall back to 32px when overflowBtn.offsetWidth === 0 (hidden on the
first render) so the initial width measurement is not off.