Broadcasts: Disabling "Results" should hide them from single-board view

[AAArmstark]

Disabling the recently introduced broadcast "Results" option (#16650) doesn't hide the results from the single-board game view, so users cannot play through any moves without seeing the results again, defeating the purpose of the option.

For example: https://lichess.org/broadcast/prague-open-2025--im-open/round-8/sxGrKfFM/76zCqJGq

Instead, the result could be displayed only on (or after) the final move, or it could always be hidden, but the user would then need another button in the single-board game view to display the result whenever they want (without going back to the multi-board view).

[yafred]

Same for the PGN ? It's a spoiler too ?

[AAArmstark]

• moves in the notation could only become visible after the user made them on the board (similar to the "hide next moves" study analysis mode)
  so instead of this:
  we would have this:

• analysis, annotations, arrows could be disabled automatically (users can already do that themselves though)
  

• variations could be removed as they spoiler that the player made a mistake
  

• pgn tags and computer analysis buttons could be removed from the bar below the board
  

(and I realized that the multi-board view below the board already allows to toggle the results, so a new button, as I suggested before, might not be needed)

[SergioGlorias]

maybe hiding the moves will be a bit tricky, but hiding the result until the last move would help

[yafred]

@SergioGlorias I am reading the code at the moment and I think there may be a way to add to the extend the Conceal concept to achieve what I think @AAArmstark would expect

The way I see it, when you have unchecked the 'show results' box:

• Clicking on a board in the multiboard area would open the 'game' (actually the study chapter) at the initial position with the moves hidden and the result hidden (in the player headers)
• Clicking on 'jump next' would unroll the moves and unveil them in the side view (which is not possible without extending the Conceal implementation)
• When you reach the last move (either jump next or jump last), the result would appear