feat: add fairness sponsor

Author: ginifizz

pwa/data/con/2025/partners.ts

@@ -82,6 +82,13 @@ const partners: Partner[] = [
     link: "https://www.akawaka.fr/",
     rank: 2,
   },
+  {
+    name: "Fairness",
+    logo: "fairness",
+    link: "https://fairness.coop/",
+    rank: 2,
+    highlight: true,
+  },
   {
     name: "Perfect Core",
     logo: "perfect-core",