feat(website): responsive / mobile layouts

Make the marketing site mobile-friendly across every page and section.
Desktop appearance is unchanged; all breakpoint logic targets <=768px.

- Fluid section padding via clamp(); equal grids use auto-fit/minmax,
  asymmetric grids stack to one column via scoped-CSS media queries
- Nav: real hamburger menu on mobile (links, lang toggle, login, CTA)
- ProductMockup: scales the whole dashboard to fit (zoom) instead of
  reflowing its internals into a tall stack
- Lower oversized heading clamp() minimums so titles no longer overflow
  at ~390px (hero, page headers, final CTA, brand cover/chapter)
- HowItWorks: row-gap when steps stack so node markers clear the text
- Compare + partners tables: stacked rows now label each value with its
  column (Dezky vs hyperscaler / CSP) instead of an ambiguous header
- Footer columns, tiers, calculator and tables stack cleanly on mobile

apps/website/components/landing/FinalCta.vue

@@ -11,14 +11,14 @@ const copy = useCopy()
     <div :style="{ position: 'absolute', right: '-180px', bottom: '-180px', opacity: 0.05 }">
       <BrandNodeMark :size="640" :fg="C.carbon" :accent="C.signal" />
     </div>
-    <LandingContainer pad="140px 64px">
-      <h2 :style="{ fontFamily: '\'Inter Tight\', sans-serif', fontWeight: 600, fontSize: 'clamp(48px, 6vw, 96px)', letterSpacing: '-0.04em', lineHeight: 0.98, margin: 0, color: C.bone, textWrap: 'balance', maxWidth: '900px' }">
+    <LandingContainer pad="clamp(56px, 8vw, 140px) clamp(20px, 5vw, 64px)">
+      <h2 :style="{ fontFamily: '\'Inter Tight\', sans-serif', fontWeight: 600, fontSize: 'clamp(32px, 6vw, 96px)', letterSpacing: '-0.04em', lineHeight: 0.98, margin: 0, color: C.bone, textWrap: 'balance', maxWidth: '900px' }">
         <template v-for="(part, i) in copy.finalCta.heading" :key="i">
           <template v-if="typeof part === 'string'">{{ part }} </template>
           <span v-else :style="{ color: C.signal }">{{ part.hl }}</span>
         </template>
       </h2>
-      <div :style="{ marginTop: '28px', maxWidth: '520px', fontFamily: '\'Inter\', sans-serif', fontSize: '19px', color: 'rgba(244,243,238,0.7)' }">{{ copy.finalCta.sub }}</div>
+      <div :style="{ marginTop: '28px', maxWidth: 'min(100%, 520px)', fontFamily: '\'Inter\', sans-serif', fontSize: '19px', color: 'rgba(244,243,238,0.7)' }">{{ copy.finalCta.sub }}</div>
       <div :style="{ marginTop: '40px' }">
         <button :style="{
           background: C.signal, color: C.carbon, border: 'none',