Virtualize All Systems table to improve performance with hundreds of systems (#1100)

- Also truncate long system names in tables and alerts sheet. (#1104)

beszel/site/src/components/ui/table.tsx

@@ -13,7 +13,11 @@ Table.displayName = "Table"
 
 const TableHeader = React.forwardRef<HTMLTableSectionElement, React.HTMLAttributes<HTMLTableSectionElement>>(
 	({ className, ...props }, ref) => (
-		<thead ref={ref} className={cn("bg-muted/30 [&_tr]:border-b", className)} {...props} />
+		<thead
+			ref={ref}
+			className={cn("bg-table-header border-b border-border/50 [&_tr]:border-b", className)}
+			{...props}
+		/>
 	)
 )
 TableHeader.displayName = "TableHeader"