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>

scripts/prod-check.mjs

@@ -1,23 +0,0 @@
-import { chromium } from 'playwright';
-const browser = await chromium.launch();
-const ctx = await browser.newContext({ viewport: { width: 390, height: 844 }, isMobile: true, hasTouch: true, deviceScaleFactor: 2 });
-const page = await ctx.newPage();
-await page.goto('https://yslootahrobotics.com/', { waitUntil: 'networkidle', timeout: 60000 });
-await page.waitForSelector('footer', { timeout: 30000 });
-await page.waitForTimeout(3000);
-const r = await page.evaluate(() => {
-  const footer = document.querySelector('footer');
-  if (!footer) return { error: 'no footer' };
-  const body = document.body;
-  const fRect = footer.getBoundingClientRect();
-  return {
-    bodyScrollHeight: body.scrollHeight,
-    footerBottomAbs: Math.round(fRect.bottom + window.scrollY),
-    spaceBelowFooter: Math.round(body.scrollHeight - (fRect.bottom + window.scrollY)),
-    bodyDisplay: getComputedStyle(body).display,
-    bodyMinHeight: getComputedStyle(body).minHeight,
-    footerMarginTop: getComputedStyle(footer).marginTop,
-  };
-});
-console.log(JSON.stringify(r, null, 2));
-await browser.close();