Update the website's favicon to a branded monogram

Replace the existing favicon SVG with a new one featuring a JH monogram in the brand's indigo color.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 6f3329ae-2dcc-46cc-bf2e-f58b7a5fa805
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Event-Id: 197782a0-f55c-4162-8d73-04f8aa2d0421
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/e678fe28-87ab-4437-945b-7a15e872a292/6f3329ae-2dcc-46cc-bf2e-f58b7a5fa805/vRxTy2Z
Replit-Helium-Checkpoint-Created: true

artifacts/joachim-portfolio/public/favicon.svg

@@ -1,3 +1,13 @@
-<svg width="180" height="180" viewBox="0 0 180 180" fill="none" xmlns="http://www.w3.org/2000/svg">
-<rect width="180" height="180" rx="36" fill="#FF3C00"/>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32" width="32" height="32">
+  <rect width="32" height="32" rx="8" fill="#3f4ff4"/>
+  <text
+    x="16"
+    y="22"
+    font-family="Inter, Arial, sans-serif"
+    font-size="13"
+    font-weight="700"
+    fill="white"
+    text-anchor="middle"
+    letter-spacing="-0.5"
+  >JH</text>
 </svg>