feat: finalize logo — git branch tree forming 'm'

Design B chosen: bold top-down git tree with three branches.
Second fork nearly at same height as first for balanced 'm' shape.
Applied to logo.svg, favicon.svg, and homepage hero.
Restored clean homepage layout (removed design picker).

public/assets/img/logo.svg

@@ -1,34 +1,26 @@
-<svg xmlns="http://www.w3.org/2000/svg" width="200" height="200" viewBox="0 0 200 200">
+<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg">
   <defs>
     <linearGradient id="mgitGrad" x1="0%" y1="0%" x2="100%" y2="100%">
       <stop offset="0%" stop-color="#3b82f6"/>
       <stop offset="100%" stop-color="#1e40af"/>
     </linearGradient>
   </defs>
-  <!-- Background -->
   <rect width="200" height="200" fill="url(#mgitGrad)" rx="40"/>
-
-  <!-- Git branch lines -->
-  <g stroke="#ffffff" stroke-width="5" stroke-linecap="round" fill="none" opacity="0.35">
-    <!-- Main branch (vertical) -->
-    <line x1="70" y1="45" x2="70" y2="155"/>
-    <!-- Feature branch curving out and back -->
-    <path d="M70,75 C70,75 100,60 115,55"/>
-    <path d="M70,120 C70,120 100,135 115,140"/>
-    <!-- Second branch -->
-    <path d="M115,55 L115,140"/>
+  <g stroke="#ffffff" stroke-width="8" stroke-linecap="round" fill="none">
+    <line x1="45" y1="40" x2="45" y2="160"/>
+    <path d="M45,72 C65,62 80,62 100,72"/>
+    <line x1="100" y1="72" x2="100" y2="160"/>
+    <path d="M100,80 C120,70 135,70 155,80"/>
+    <line x1="155" y1="80" x2="155" y2="160"/>
   </g>
-
-  <!-- Branch nodes -->
-  <g fill="#ffffff" opacity="0.4">
-    <circle cx="70" cy="45" r="6"/>
-    <circle cx="70" cy="155" r="6"/>
-    <circle cx="115" cy="55" r="6"/>
-    <circle cx="115" cy="140" r="6"/>
-    <circle cx="70" cy="75" r="4"/>
-    <circle cx="70" cy="120" r="4"/>
+  <g fill="#ffffff">
+    <circle cx="45" cy="40" r="9"/>
+    <circle cx="45" cy="72" r="7"/>
+    <circle cx="100" cy="72" r="7"/>
+    <circle cx="100" cy="80" r="7"/>
+    <circle cx="155" cy="80" r="7"/>
+    <circle cx="45" cy="160" r="9"/>
+    <circle cx="100" cy="160" r="9"/>
+    <circle cx="155" cy="160" r="9"/>
   </g>
-
-  <!-- 'm' lettermark -->
-  <text x="100" y="135" font-family="Inter, -apple-system, system-ui, sans-serif" font-size="100" font-weight="700" fill="#ffffff" text-anchor="middle" letter-spacing="-4">m</text>
 </svg>