feat(site): one voice, brand gradients, a lighter splash gate, denser portfolio

- Voice unified on the title-tag register: the homepage h1 now says what we
  sell (Custom E-commerce, Apps & Crypto Tools); 'Precision engineering for
  everyone' is demoted to the supporting line. The structured-data and
  manifest descriptions now match the OG description instead of carrying
  their own registers.
- The off-palette cyan/blue gradients are gone: .hero-title and the new
  .brand-gradient-text use the four-colour system (light palette on light,
  dark palette on dark, per the pack). Splash cover text, services and
  portfolio headings, the hero aura, and button shadows all follow.
- The splash now dismisses once 40% scrolled past instead of requiring the
  whole screen to leave the viewport (it was already once-per-session and
  reduced-motion-skipping).
- Portfolio: heading 'Portfolio', subtitle 'Products & projects', meta title
  to match; grid grows to three columns on xl in a max-w-6xl container.
- anim3_matrix slimmed: single-layer glow, unfiltered crackle and orbs, and
  the border cycles stroke colour instead of animating filter:hue-rotate --
  the filter animation forced a full filter re-render per frame and pegged a
  core on the page hosting it.

apps/web/src/app/services/page.tsx

@@ -33,7 +33,7 @@ export default function ServicesPage() {
       <div id="main-content" className="z-10 w-full max-w-5xl mx-auto py-20 px-4">
         {/* Page header */}
         <div className="text-center mb-12">
-          <h1 className="text-4xl md:text-6xl font-bold mb-6 pb-3 bg-clip-text text-transparent bg-gradient-to-r from-emerald-400 to-blue-500">
+          <h1 className="text-4xl md:text-6xl font-bold mb-6 pb-3 brand-gradient-text">
             What we build
           </h1>
           <p className="text-xl text-muted-foreground max-w-2xl mx-auto">