Upgrade to Effect v4

packages/webapp/package.json

@@ -14,9 +14,6 @@
     "clean:modules": "rm -rf node_modules"
   },
   "dependencies": {
-    "@effect/platform": "^0.96.1",
-    "@effect/platform-browser": "^0.76.0",
-    "@effect/rpc": "^0.75.1",
     "@fontsource/work-sans": "^5.2.8",
     "@radix-ui/react-slot": "^1.2.4",
     "@radix-ui/react-tooltip": "^1.2.8",
@@ -24,8 +21,7 @@
     "@website/common": "workspace:*",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
-    "effect": "^3.21.2",
-    "effect-fc": "^0.2.6",
+    "effect": "4.0.0-beta.101",
     "i18next": "^26.2.0",
     "i18next-browser-languagedetector": "^8.2.1",
     "lucide-react": "^1.16.0",