Use hub 'name' in routes & add top-post sorting

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).

backend/vontor_cz/pagination.py

@@ -18,6 +18,15 @@ class CreatedCursorPagination(CursorPagination):
     max_page_size = 100
 
 
+class TopPostsCursorPagination(CursorPagination):
+    """Cursor pagination ordered by vote score descending, then by id descending as tiebreaker."""
+    page_size = 20
+    ordering = ('-vote_score', '-id')
+    cursor_query_param = 'cursor'
+    page_size_query_param = 'page_size'
+    max_page_size = 100
+
+
 class CreatedAscCursorPagination(CursorPagination):
     """Cursor pagination ordered by `created_at` (oldest first).