perf: optimize Lighthouse scores to 100

Performance:
- Lazy-load ShaderGradientBackground via dynamic import (reduces initial JS ~250KB)
- Disable ShaderGradient animations (animate=off) to reduce CPU/GPU load
- Remove opacity:0 animations from Hero LCP elements for instant paint
- Add browserslist targeting modern browsers (eliminates ~13KB polyfills)

Accessibility:
- Fix color contrast: text-stone-400 → text-stone-600 dark:text-stone-400 on light backgrounds
- Fix text-liquid-mint → text-emerald-700/600 for readable text/accent dots
- Fix quote text contrast on dark status box (text-stone-700 → text-stone-300)
- Fix Online badge contrast (emerald-600 → emerald-700)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

app/components/ClientProviders.tsx

@@ -14,6 +14,11 @@ const BackgroundBlobs = dynamic(() => import("@/components/BackgroundBlobs").cat
   loading: () => null,
 });
 
+const ShaderGradientBackground = dynamic(
+  () => import("./ShaderGradientBackground"),
+  { ssr: false, loading: () => null }
+);
+
 export default function ClientProviders({
   children,
 }: {
@@ -100,6 +105,7 @@ function GatedProviders({
     <ErrorBoundary>
       <ToastProvider>
         {mounted && <BackgroundBlobs />}
+        {mounted && <ShaderGradientBackground />}
         <div className="relative z-10">{children}</div>
       </ToastProvider>
     </ErrorBoundary>