Rename SideMenu to NavMenu, fix tooltips, and update react-zen.

- Rename SideMenu to NavMenu with visible group title labels and selected item highlighting
- Update react-zen to 0.242.0 and fix responsive breakpoints (xs -> base)
- Style floating tooltips with inverted background across WorldMap, charts, and WeeklyTraffic
- Add CSS variables for primary color and use IconLabel consistently
- Remove stray console.log from LoadingPanel

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/(main)/websites/[websiteId]/WebsiteControls.tsx

@@ -23,11 +23,11 @@ export function WebsiteControls({
 }) {
   return (
     <Column gap>
-      <Grid columns={{ xs: '1fr', md: 'auto 1fr' }} gap>
+      <Grid columns={{ base: '1fr', md: 'auto 1fr' }} gap>
         <Row alignItems="center" justifyContent="flex-start" gap="4">
           {allowFilter && <WebsiteFilterButton websiteId={websiteId} />}
         </Row>
-        <Row alignItems="center" justifyContent={{ xs: 'flex-start', md: 'flex-end' }}>
+        <Row alignItems="center" justifyContent={{ base: 'flex-start', md: 'flex-end' }}>
           {allowDateFilter && (
             <WebsiteDateFilter websiteId={websiteId} allowCompare={allowCompare} />
           )}