Add transparent-background Lookatu logo and mark

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013TAaJBzbmePTECuv62BXYX

lookatu-logo/lookatu-mark.svg

@@ -0,0 +1,3 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="20 8 216 246" role="img" aria-label="Lookatu mark"><defs><linearGradient id="g" x1="0" y1="0" x2="0" y2="1"><stop offset="0" stop-color="#1FB5C0"/><stop offset="1" stop-color="#0B5E8A"/></linearGradient></defs><path d="M128 14 L226 48 V122 C226 182 184 226 128 246 C72 226 30 182 30 122 V48 Z" fill="url(#g)"/>
+<path d="M128 62 C98 62 76 84 76 112 C76 148 112 176 128 198 C144 176 180 148 180 112 C180 84 158 62 128 62 Z" fill="#fff"/>
+<circle cx="128" cy="112" r="26" fill="#0E7C86"/><circle cx="128" cy="112" r="13" fill="#FFC53D"/><circle cx="134" cy="106" r="4.5" fill="#fff"/></svg>