Add setting to change time before a repeat is allowed in continuous radio mode - #1630

Changes

A picture is worth a thousand words

Add "Allow repeats after" setting in radio menu, visible only when continuous mode is selected (currently appears without any animation), with 90 used as default but set to 5 on screenshot. If field is empty but submitted, it resets to 0, disabling repetition entirely and thus fixing #1610.

I should say that, since I don't know flutter well, I decided to slow things down and run OpenCode+gemma4-26b/llama.cpp+superpowers to write UI code (the latter commit, positive branch of if statement only; that plugin was simply installed, listed for completeness). Since resulting UI was very poor, I added leading icon much like ChoiceMenuOption, fixed onSubmitted to reset to 0 on invalid submit and split title to title and subtitle. I say it's 50/50 and I checked it with other code so it looks good to me.

^{It might be a good idea to extract this option into reusable widget, but it's currently used in choice list so idk, it's definitely not a choice}

It looks strange since there is some delay between mode selection and sheet closure (remove the delay?), however my idea, I think, has some point:

• Burying it in settings has no value and settings are already burdened
• Keeping it near radio menu allows to use less words to explain this setting
• This setting is shown briefly before the sheet is closed due to change in radio mode
  • This is a loss to UX, sure, but this setting is not to be changed often
  • User can open sheet again to change the setting
  • This conveys a clear message "you don't need to change it if you don't want"
  • This also clearly shows relationship between continuous mode and this option and actually guides user about its impact
  • But looks like a bug :-(

I almost said i can't test it but I finally found it (1 minute is used):

You just need an artist so unique it doesn't find anything closer than his other tracks

Great album btw. Calming.

Alternatives

• Just made it up - somehow query jellyfin on total library size.
• 1 hour later - make it a toggle? 90 minutes or no repeats at all?

Todo before merging

• Translations
• Reset Settings - ???
  • This setting is clearly visible when "Continuous" mode is used and has direct and understandable impact, so I guess doesn't matter?

Related Issues

Fixes #1610