Show full playoff bracket, mark series results, harden API decoding

Playoffs:
- List every round played so far (Round 1 → current) instead of only the
  current round, on both macOS menu and iPhone
- Strike through the eliminated team's tricode in a finished series and drop
  the now-redundant "(Final … wins)" tag on completed earlier rounds
- Refetch the bracket when a finished game implies more completed games than
  the cached bracket records, so the series score and round no longer get
  stuck on stale data after cold launch or the NHL bracket endpoint's lag

API robustness:
- Tolerate optional gameCenterLink/startTimeUTC on TBD playoff matchups so the
  scoreboard decode no longer aborts
- Reject API state regressions via a monotonic FUT→…→OFF progression rank so a
  brief glitch can't downgrade a finished game back to "-:-"

IceGlass-iOS/ViewModel/ScoreboardViewModel.swift

@@ -40,14 +40,9 @@ final class ScoreboardViewModel {
         return MainService.shared.gamesByDate
     }
 
-    var currentRoundSeriesItems: [MainService.RoundSeriesItem] {
+    var roundSeriesGroups: [MainService.RoundGroup] {
         _ = revision
-        return MainService.shared.currentRoundSeriesItems
-    }
-
-    var currentRoundNumber: Int? {
-        _ = revision
-        return MainService.shared.bracket?.currentRound
+        return MainService.shared.roundSeriesGroups
     }
 
     /// Bridge object that forwards MainService callbacks back to this view model.