feat: distribute animated DrillBitSpinner across all major components as a background watermark

Former-commit-id: ad28a5d93b773be795cd0d73fd6ed2accd257a10

components/blocks/ReferencesSlider.tsx

@@ -6,6 +6,7 @@ import Link from 'next/link';
 import Image from 'next/image';
 import { HoverShineOverlay } from '@/components/ui/HoverShineOverlay';
 import { DrillOrbit } from '@/components/ui/decorations/DrillOrbit';
+import { DrillBitSpinner } from '@/components/ui/decorations/DrillBitSpinner';
 
 export interface Reference {
   id: string;
@@ -152,6 +153,10 @@ export function ReferencesSlider(props: ReferencesSliderProps) {
           <svg xmlns="http://www.w3.org/2000/svg" className="w-5 h-5" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2.5" strokeLinecap="round" strokeLinejoin="round"><line x1="5" y1="12" x2="19" y2="12"></line><polyline points="12 5 19 12 12 19"></polyline></svg>
         </Link>
       </div>
+      {/* Decorative: large abstract drill bit spinning slowly in background */}
+      <div className="absolute top-1/2 -translate-y-1/2 -right-48 pointer-events-none opacity-[0.03]">
+        <DrillBitSpinner size={600} duration={25} glow={false} />
+      </div>
       {/* Decorative: abstract HDD bore trajectory */}
       <DrillOrbit side="left" />
     </section>