Add support for up to 6 players.

internal/ai/ai.go

@@ -247,11 +247,18 @@ func immediateWeight(v *game.View) float64 {
 	if v.MaxRounds > 1 {
 		w += 0.60 * float64(v.Round-1) / float64(v.MaxRounds-1)
 	}
-	me := v.Players[v.YouSeat]
+	// How far behind the field the bot is. The yardstick is whoever is leading,
+	// not the sum of everyone — at a six-player table the title is a race
+	// against the front-runner, and summing would swamp the round term.
+	me := v.PlayerView(v.YouSeat)
+	best := 0
 	for _, p := range v.Players {
 		if p.Seat != v.YouSeat {
-			w += 0.08 * float64(p.Trophies-me.Trophies)
+			best = max(best, p.Trophies)
 		}
 	}
+	if me != nil {
+		w += 0.08 * float64(best-me.Trophies)
+	}
 	return min(max(w, 0.25), 1)
 }