Allow arbitrary route meta

Describe the feature

Expose the route meta in event, so we can do something like mentioned below similar to nuxt middlewares

// server/api/index.ts
defineRouteMeta({
  public: true,
});

export default defineEventHandler((event) => {
  return "Start by editing <code>server/routes/index.ts</code>.";
});

// middleware/auth.ts
export default defineEventHandler((event) => {
  const meta = getRouteMeta(event)
  if (meta.public) return
  
  // auth logic
});

Additional information

• Would you be willing to help implement this feature?

Start with the example entry points in server/api/index.ts and middleware/auth.ts, then trace how route definitions and event context are exposed. Determine how arbitrary metadata should be attached to a route and retrieved with getRouteMeta(event). Done means defineRouteMeta({ public: true }) is available and middleware can read that value from the event.