Add nomination submission and bidding start workflow

- Added `BID_START_REQUEST` and `NOMINATION_SUBMIT_REQUEST` handling in backend consumers.
- Extended draft state to include `current_movie` and `bids` cache keys.
- Updated frontend to:
  - Allow participants to nominate movies when it's their turn.
  - Enable admins to start bidding for the nominated movie.
  - Highlight the current nominated movie and the current user.
- Synced state updates across clients via WebSocket events.

draft/constants.py

@@ -30,6 +30,7 @@ class DraftMessage(StrEnum):
 
     # Bidding (examples, adjust to your flow)
     BID_START_INFORM         = "bid.start.inform"             # server -> client (movie, ends_at)
+    BID_START_REQUEST        = "bid.start.request"             # server -> client (movie, ends_at)
     BID_PLACE_REQUEST        = "bid.place.request"            # client -> server (amount)
     BID_UPDATE_INFORM        = "bid.update.inform"            # server -> client (high bid)
     BID_END_INFORM           = "bid.end.inform"               # server -> client (winner)