Make the server-list toolbar's expand/collapse toggle and open/close-monitoring
icons the same width and spacing as the header's theme / client-settings icons:
- ListToggle (default variant), PinColumnButton, and the MonitoringControls
close button now render as `ActionIcon variant="subtle" size={36}` (glyph 20),
matching the header's 36px ActionIcons, instead of wider `Button`s.
- ServerListControls uses `gap="sm"` so its buttons sit the same 12px apart as
the header's RightSection controls.
Update a TaskListPanel test that found the toggle by a brittle
`mantine-Button-root` class to select it by its accessible name instead.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BrihGWcrM9JGRyu41nzZYw
ea8715c9c4