Switch hub endpoints to use the hub `name` slug and update frontend routes/clients accordingly. Backend: HubViewSet now uses lookup_field='name'; PostViewSet list supports `sort=top` with vote_score annotation and time windows/custom ranges, and a new TopPostsCursorPagination was added. Frontend: routes changed from `/hub/:id` to `/h/:name`, the generated hubs API was updated from id->name, and the hub feed client accepts `sort`, `time`, `start`, and `end` params (query key updated). Also adds new homepage UI components (HeroSection, DroneSection) and navbar improvements (scroll state, auto-close mobile menu on route changes, and small icon/class tweaks).