Point fixes: badge radius, DHCP Type header, one-line Zones dates, top list headers

Badges keep the installed style's radius instead of a pill; the Leases Type column
gets its visible header; Zones dates no longer wrap; the Dashboard's top lists use
the standard panel header height; DHCP reads the clock with the list, not in render.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/ui/Tag.tsx

@@ -44,7 +44,7 @@ const VARIANT: Record<TagTone, BadgeProps['variant']> = {
 
 export function Tag({ tone = 'neutral', children }: { tone?: TagTone; children: ReactNode }) {
   return (
-    <Badge variant={VARIANT[tone]} radius="full" className={tone === 'neutral' ? undefined : `tag-${tone}`}>
+    <Badge variant={VARIANT[tone]} className={tone === 'neutral' ? undefined : `tag-${tone}`}>
       {children}
     </Badge>
   )