Next.js 16, React 19.2, Identities page, Invitations identities step, PNPM Catalogs (#381)

* Upgraded to Next.js 16
* Refactored code to comply with React 19.2 ESLint rules
* Refactored some useEffect usages with the new useEffectEvent
* Added Identities page and added second step to set up an identity after accepting an invitation
* Updated all dependencies
* Introduced PNPM catalogs for some frequently updated dependencies
* Bugs fixing and improvements

tooling/prettier/package.json

@@ -11,7 +11,7 @@
   "dependencies": {
     "@trivago/prettier-plugin-sort-imports": "5.2.2",
     "prettier": "^3.6.2",
-    "prettier-plugin-tailwindcss": "^0.6.14"
+    "prettier-plugin-tailwindcss": "^0.7.1"
   },
   "devDependencies": {
     "@kit/tsconfig": "workspace:*",