feat: enhance jobs list stats with tooltips, icons, and refresh count

- Add Tooltip UI component for styled hover tooltips
- Replace native title attributes with Tooltip on all job stats
- Add refresh icon (green) showing actual refreshed count for metadata refresh
- Add icon+tooltip to scanned files stat
- Add icon prop to StatBox component
- Add refreshed field to stats_json types
- Distinct tooltip labels for total links vs refreshed count

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

apps/backoffice/app/components/ui/Tooltip.tsx

@@ -0,0 +1,18 @@
+import { ReactNode } from "react";
+
+interface TooltipProps {
+  label: string;
+  children: ReactNode;
+  className?: string;
+}
+
+export function Tooltip({ label, children, className = "" }: TooltipProps) {
+  return (
+    <span className={`relative group/tooltip inline-flex ${className}`}>
+      {children}
+      <span className="pointer-events-none absolute bottom-full left-1/2 -translate-x-1/2 mb-2 px-2.5 py-1 text-xs text-popover-foreground bg-popover border border-border rounded-lg shadow-lg whitespace-nowrap opacity-0 scale-95 transition-all duration-150 group-hover/tooltip:opacity-100 group-hover/tooltip:scale-100 z-50">
+        {label}
+      </span>
+    </span>
+  );
+}