feat: premium landing page, Swagger UI docs, full OG meta stack

- Premium landing page with nav, hero, stats, streaming flow, endpoint cards
- Full OG meta stack (OG, Twitter Card, JSON-LD WebAPI schema)
- SVG favicon matching miruro.tv icon style
- SVG share image for social sharing (1200x630)
- Dedicated docs.html with custom header and Swagger UI styling
- Canonical URLs, theme-color, robots meta
- Apple-touch-icon and mask-icon from miruro.tv
- Responsive design (mobile-friendly)
- Font: Inter (Google Fonts)

public/favicon.svg

@@ -0,0 +1,18 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512">
+  <defs>
+    <linearGradient id="bg" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" style="stop-color:#38bdf8"/>
+      <stop offset="50%" style="stop-color:#818cf8"/>
+      <stop offset="100%" style="stop-color:#a78bfa"/>
+    </linearGradient>
+    <linearGradient id="shine" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" style="stop-color:rgba(255,255,255,0.3)"/>
+      <stop offset="100%" style="stop-color:rgba(255,255,255,0)"/>
+    </linearGradient>
+  </defs>
+  <rect width="512" height="512" rx="96" fill="url(#bg)"/>
+  <rect width="512" height="256" rx="96" fill="url(#shine)"/>
+  <text x="256" y="310" text-anchor="middle" fill="white" font-family="Arial Black,Helvetica Neue,sans-serif" font-size="260" font-weight="900" letter-spacing="-10">M</text>
+  <circle cx="390" cy="140" r="24" fill="rgba(255,255,255,0.9)"/>
+  <circle cx="390" cy="140" r="12" fill="url(#bg)"/>
+</svg>