fix(linea-ens-app): failing build process

[alainncls]

Note

Fixes build by adjusting TypeScript config and adding missing type declarations, updates PoH links to Linea Hub, and removes an obsolete reminder test.

• Build/TypeScript:
  • Remove /// <reference path="./.next/types/routes.d.ts" /> from next-env.d.ts.
  • Update tsconfig.json includes: drop vitest.config.mts; add typings-custom/**/*.d.ts.
  • Add custom typings typings-custom/react-confetti.d.ts.
• Frontend:
  • Update PoH acquisition link to Linea Hub in README.md and PohCheck.tsx action button (https://linea.build/hub/).
• Tests:
  • Remove reminder-related action and modal test from ExpirySection.test.tsx; keep extend action test.

^{Written by Cursor Bugbot for commit 02133ec. This will update automatically on new commits. Configure here.}