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

Former-commit-id: ad28a5d93b773be795cd0d73fd6ed2accd257a10

components/blocks/CompetenceBentoGrid.tsx

@@ -7,6 +7,7 @@ import { useState, useEffect } from 'react';
 import { Button } from '@/components/ui/Button';
 import { HoverShineOverlay } from '@/components/ui/HoverShineOverlay';
 import { StratumLines } from '@/components/ui/decorations/StratumLines';
+import { DrillBitSpinner } from '@/components/ui/decorations/DrillBitSpinner';
 
 interface CompetenceBentoGridProps {
   badge?: string;
@@ -168,6 +169,10 @@ export function CompetenceBentoGrid(props: CompetenceBentoGridProps) {
           })}
         </div>
       </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 earth strata / excavation layers */}
       <StratumLines placement="bottom-left" invert />
       <StratumLines placement="bottom-right" invert />