discard puzzle theme flood

modules/puzzle/src/main/PuzzleApi.scala

@@ -106,7 +106,8 @@ final class PuzzleApi(
           round.themeVote(theme, vote) ?? { newThemes =>
             import PuzzleRound.{ BSONFields => F }
             val update =
-              if (newThemes.isEmpty) fuccess($unset(F.themes, F.puzzle).some)
+              if (newThemes.isEmpty || !PuzzleRound.themesLookSane(newThemes))
+                fuccess($unset(F.themes, F.puzzle).some)
               else
                 vote match {
                   case None =>

modules/puzzle/src/main/PuzzleRound.scala

@@ -47,6 +47,10 @@ object PuzzleRound {
 
   case class Theme(theme: PuzzleTheme.Key, vote: Boolean)
 
+  // max 7 theme upvotes
+  // unlimited downvotes
+  def themesLookSane(themes: List[Theme]): Boolean = themes.count(_.vote) < 8
+
   object BSONFields {
     val id     = "_id"
     val win    = "w"