Contributors: switch new 4 testers to custom avatars

Replace the temporary github.com/<handle>.png placeholders with the
project's standard raw.githubusercontent.com/.../images/avatars/<name>.png
pattern used by every other contributor on the page.

Added avatar files:
- images/avatars/heriberto.png
- images/avatars/JF_Carr.png   (renamed from JF_Car.png on disk so the
                                filename matches the display name)
- images/avatars/rafapuerta.png
- images/avatars/JcMinarro.png

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/app/[locale]/docs/about/contributors/page.tsx

@@ -54,30 +54,26 @@ const contributors: Contributor[] = [
     roleKey: "testing",
     avatar: "https://raw.githubusercontent.com/MacRimi/ProxMenux/main/images/avatars/Kamunhas.png",
   },
-  // Added 2026-05-31 after the v1.2.2 release. Defaulted to "testing"
-  // and GitHub's avatar service so the entries work immediately
-  // without needing avatar files uploaded under /images/avatars/.
-  // Swap to a per-contributor /images/avatars/<name>.png once the
-  // custom artwork is ready.
+  // Added 2026-05-31 after the v1.2.2 release.
   {
     name: "heriberto",
     roleKey: "testing",
-    avatar: "https://github.com/heriberto.png",
+    avatar: "https://raw.githubusercontent.com/MacRimi/ProxMenux/main/images/avatars/heriberto.png",
   },
   {
     name: "JF_Carr",
     roleKey: "testing",
-    avatar: "https://github.com/JF_Carr.png",
+    avatar: "https://raw.githubusercontent.com/MacRimi/ProxMenux/main/images/avatars/JF_Carr.png",
   },
   {
     name: "rafapuerta",
     roleKey: "testing",
-    avatar: "https://github.com/rafapuerta.png",
+    avatar: "https://raw.githubusercontent.com/MacRimi/ProxMenux/main/images/avatars/rafapuerta.png",
   },
   {
     name: "JcMinarro",
     roleKey: "testing",
-    avatar: "https://github.com/JcMinarro.png",
+    avatar: "https://raw.githubusercontent.com/MacRimi/ProxMenux/main/images/avatars/JcMinarro.png",
   },
 ]