polish: consolidate typography to next/font variables, add atelier utility classes

- Remove Google Fonts @import from 4 components (SiteHeader, LandingPageWrapper,
  TestimonialsAndCTA, FeaturesAndStats) — eliminate render-blocking external
  request and font flash
- Replace all unloaded Cormorant Garamond / Playfair Display / DM Sans /
  Plus Jakarta Sans references with the existing next/font variables
  (Fraunces, Manrope, Fragment_Mono) — visual coherence with the design system
- Update 9 pages (blog, brands, changelog, maintenance, protected-example,
  roadmap, security, waitlist, WaitlistForm) to use the loaded Fraunces
- Fix dead --font-geist / --font-jetbrains-mono references in
  admin-design-system.css (now point to --font-manrope / --font-fragment-mono
  which are actually loaded)
- Add atelier-pill, atelier-numerals, atelier-fineprint, atelier-canvas-soft
  utility classes; .atelier-input:focus-visible refined ring
- Add .ha-field-textarea, .ha-scroll, .ha-skeleton to admin design system
- Extend prefers-reduced-motion guard to atelier-enter/stagger/shimmer
- Apply atelier-fineprint to login/not-found/error pages for consistency
- No structural changes; build passes, 0 type errors

src/components/landing/FeaturesAndStats.tsx

@@ -231,22 +231,20 @@ export default function FeaturesAndStats() {
   return (
     <div
       style={{
-        fontFamily: "'Plus Jakarta Sans', sans-serif",
+        fontFamily: "var(--font-manrope)",
         background: "#faf8f5",
         color: "#1a1a1a",
         minHeight: "100vh",
       }}
     >
       <style jsx>{`
-        @import url("https://fonts.googleapis.com/css2?family=Cormorant+Garamond:ital,wght@0,400;0,500;0,600;0,700;1,400&display=swap");
-
         :global(body) {
           margin: 0;
           padding: 0;
         }
 
         .section-label {
-          font-family: "Plus Jakarta Sans", sans-serif;
+          font-family: var(--font-manrope);
           font-size: 0.75rem;
           font-weight: 600;
           letter-spacing: 0.15em;
@@ -256,7 +254,7 @@ export default function FeaturesAndStats() {
         }
 
         .section-title {
-          font-family: "Cormorant Garamond", serif;
+          font-family: var(--font-fraunces);
           font-size: clamp(2rem, 5vw, 3rem);
           font-weight: 600;
           color: #1a4d2e;
@@ -265,7 +263,7 @@ export default function FeaturesAndStats() {
         }
 
         .section-subtitle {
-          font-family: "Plus Jakarta Sans", sans-serif;
+          font-family: var(--font-manrope);
           font-size: 1.125rem;
           color: #4a4a4a;
           line-height: 1.6;
@@ -304,7 +302,7 @@ export default function FeaturesAndStats() {
         }
 
         .feature-title {
-          font-family: "Cormorant Garamond", serif;
+          font-family: var(--font-fraunces);
           font-size: 1.375rem;
           font-weight: 600;
           color: #1a4d2e;
@@ -326,7 +324,7 @@ export default function FeaturesAndStats() {
         }
 
         .stat-number {
-          font-family: "Cormorant Garamond", serif;
+          font-family: var(--font-fraunces);
           font-size: clamp(2.5rem, 5vw, 4rem);
           font-weight: 700;
           color: #1a4d2e;
@@ -570,7 +568,7 @@ export default function FeaturesAndStats() {
             <span
               style={{
                 display: "block",
-                fontFamily: "'Plus Jakarta Sans', sans-serif",
+                fontFamily: "var(--font-manrope)",
                 fontSize: "0.75rem",
                 fontWeight: 600,
                 letterSpacing: "0.15em",
@@ -583,7 +581,7 @@ export default function FeaturesAndStats() {
             </span>
             <h2
               style={{
-                fontFamily: "'Cormorant Garamond', serif",
+                fontFamily: "var(--font-fraunces)",
                 fontSize: "clamp(2rem, 4vw, 2.75rem)",
                 fontWeight: 600,
                 color: "#faf8f5",
@@ -620,7 +618,7 @@ export default function FeaturesAndStats() {
               >
                 <div
                   style={{
-                    fontFamily: "'Cormorant Garamond', serif",
+                    fontFamily: "var(--font-fraunces)",
                     fontSize: "clamp(2.25rem, 4.5vw, 3.75rem)",
                     fontWeight: 700,
                     color: "#faf8f5",
@@ -660,7 +658,7 @@ export default function FeaturesAndStats() {
                 </div>
                 <p
                   style={{
-                    fontFamily: "'Plus Jakarta Sans', sans-serif",
+                    fontFamily: "var(--font-manrope)",
                     fontSize: "0.875rem",
                     fontWeight: 500,
                     color: "#6b8f71",