feat: monochrome black & white rebrand + new Pudu robots

- Convert site from royal-blue theme to black/white monochrome (desaturate
  all blue-hued colors; keep WhatsApp green and error red)
- Swap blue circular brand logo for mono YS mark; regenerate favicon/PWA icons
- Add 6 Pudu robots (CC1 Pro, MT1 Max, MT1 Vac, T600, T600 Underride, BG1 Pro)
- Fix favicon.ico to RGBA (Next 16 Turbopack decode) and Stripe apiVersion type

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/book-demo/page.tsx

@@ -21,7 +21,7 @@ export default function BookDemoPage() {
             <h1 style={{ margin: 0, fontSize: 'clamp(2rem, 5vw, 3.2rem)', fontWeight: 300, lineHeight: 1.05, letterSpacing: '-0.03em' }}>
               <span className="text-gradient" style={{ fontWeight: 500 }}>See the future in person.</span>
             </h1>
-            <p style={{ margin: 0, color: '#DEE0F0', fontSize: 'clamp(0.95rem, 2vw, 1.05rem)', lineHeight: 1.7 }}>
+            <p style={{ margin: 0, color: '#e7e7e7', fontSize: 'clamp(0.95rem, 2vw, 1.05rem)', lineHeight: 1.7 }}>
               Book a live robot demo at our Dubai showroom or schedule an on-site demo at your venue. Our team will tailor the demo to your use case before you arrive.
             </p>
 
@@ -32,8 +32,8 @@ export default function BookDemoPage() {
                 'Walk through configuration and deployment options',
                 'Get UAE-specific pricing and availability',
               ].map((b) => (
-                <li key={b} style={{ display: 'flex', alignItems: 'flex-start', gap: '0.625rem', color: '#DEE0F0', lineHeight: 1.55 }}>
-                  <span style={{ width: 8, height: 8, marginTop: 8, borderRadius: 999, background: '#DEE0F0', flex: 'none' }} />
+                <li key={b} style={{ display: 'flex', alignItems: 'flex-start', gap: '0.625rem', color: '#e7e7e7', lineHeight: 1.55 }}>
+                  <span style={{ width: 8, height: 8, marginTop: 8, borderRadius: 999, background: '#e7e7e7', flex: 'none' }} />
                   {b}
                 </li>
               ))}