perf: optimize PageSpeed Insights performance

- Suppress browser source map references to fix 404/SyntaxErrors
- Reduce legacy JS polyfills via browserslist config
- Optimize LCP by refining Hero animations and image sizes
- Implement video lazy loading and reduce SVG animation complexity
- Add preconnect hints for critical origins

components/home/HeroIllustration.tsx

@@ -154,15 +154,15 @@ export default function HeroIllustration() {
             <stop offset="70%" stopColor="white" stopOpacity="0.4" />
             <stop offset="100%" stopColor="white" stopOpacity="0" />
           </linearGradient>
-          <filter id="glow" x="-50%" y="-50%" width="200%" height="200%">
-            <feGaussianBlur stdDeviation="3" result="blur" />
+          <filter id="glow" x="-20%" y="-20%" width="140%" height="140%">
+            <feGaussianBlur stdDeviation="1.5" result="blur" />
             <feMerge>
               <feMergeNode in="blur" />
               <feMergeNode in="SourceGraphic" />
             </feMerge>
           </filter>
-          <filter id="soft-glow" x="-100%" y="-100%" width="300%" height="300%">
-            <feGaussianBlur stdDeviation="2" result="blur" />
+          <filter id="soft-glow" x="-50%" y="-50%" width="200%" height="200%">
+            <feGaussianBlur stdDeviation="1" result="blur" />
             <feMerge>
               <feMergeNode in="blur" />
               <feMergeNode in="SourceGraphic" />
@@ -215,10 +215,10 @@ export default function HeroIllustration() {
           </g>
 
           {/* ANIMATED ENERGY FLOW */}
-          <g filter="url(#glow)">
+          <g>
             {POWER_LINES.map((line, i) => {
-              // Only animate a subset of lines to reduce main-thread work
-              if (i % 2 !== 0) return null;
+              // Only animate a small subset of lines to reduce main-thread work significantly
+              if (i % 5 !== 0) return null;
               const from = gridToScreen(line.from.col, line.from.row);
               const to = gridToScreen(line.to.col, line.to.row);
               const length = Math.sqrt(Math.pow(to.x - from.x, 2) + Math.pow(to.y - from.y, 2));