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/favicon.svg

@@ -1,4 +1,4 @@
-<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32" viewBox="0 0 32 32">
+<svg viewBox="0 0 32 32" xmlns="http://www.w3.org/2000/svg">
   <defs>
     <linearGradient id="favGrad" x1="0%" y1="0%" x2="100%" y2="100%">
       <stop offset="0%" stop-color="#3b82f6"/>
@@ -6,14 +6,21 @@
     </linearGradient>
   </defs>
   <rect width="32" height="32" fill="url(#favGrad)" rx="6"/>
-
-  <!-- Subtle branch lines -->
-  <g stroke="#ffffff" stroke-width="1" stroke-linecap="round" fill="none" opacity="0.3">
-    <line x1="11" y1="7" x2="11" y2="25"/>
-    <path d="M11,12 C11,12 16,10 19,9"/>
-    <line x1="19" y1="9" x2="19" y2="23"/>
+  <g stroke="#ffffff" stroke-width="1.8" stroke-linecap="round" fill="none">
+    <line x1="7" y1="6" x2="7" y2="26"/>
+    <path d="M7,11 C10,9 13,9 16,11"/>
+    <line x1="16" y1="11" x2="16" y2="26"/>
+    <path d="M16,12.5 C19,10.5 22,10.5 25,12.5"/>
+    <line x1="25" y1="12.5" x2="25" y2="26"/>
+  </g>
+  <g fill="#ffffff">
+    <circle cx="7" cy="6" r="2"/>
+    <circle cx="7" cy="11" r="1.5"/>
+    <circle cx="16" cy="11" r="1.5"/>
+    <circle cx="16" cy="12.5" r="1.5"/>
+    <circle cx="25" cy="12.5" r="1.5"/>
+    <circle cx="7" cy="26" r="2"/>
+    <circle cx="16" cy="26" r="2"/>
+    <circle cx="25" cy="26" r="2"/>
   </g>
-
-  <!-- 'm' letter -->
-  <text x="16" y="23" font-family="Inter, -apple-system, system-ui, sans-serif" font-size="18" font-weight="700" fill="#ffffff" text-anchor="middle">m</text>
 </svg>