Implement priority token.

internal/game/battle.go

@@ -195,6 +195,18 @@ func (g *Game) resolveBattle() {
 		sides[p.Seat] = s
 		res.StackSizes[p.Seat] = len(p.Deck)
 	}
+	// seatOrder resolves the priority-token holder first, then everyone else.
+	// Reveals, queued play effects, and cross-side triggers all follow it, so
+	// when two pets would act simultaneously (e.g. both throwing rocks) the
+	// holder acts first — its rocks can faint the enemy pet before that pet's
+	// own queued rocks resolve.
+	seatOrder := make([]int, 0, n)
+	seatOrder = append(seatOrder, g.PrioritySeat)
+	for seat := range sides {
+		if seat != g.PrioritySeat {
+			seatOrder = append(seatOrder, seat)
+		}
+	}
 	// Battle-prep effects that start apples in play (Monkey): they attach
 	// to the owner's first pet.
 	for _, p := range g.Players {
@@ -399,7 +411,8 @@ func (g *Game) resolveBattle() {
 		// effects queue up and resolve after all reveals (simultaneous).
 		var plays []queuedPlay
 		newlyPlayed := make([]bool, n)
-		for seat, s := range sides {
+		for _, seat := range seatOrder {
+			s := sides[seat]
 			for s.unit == nil && len(s.stack) > 0 {
 				c := s.stack[0]
 				s.stack = s.stack[1:]
@@ -447,11 +460,12 @@ func (g *Game) resolveBattle() {
 		}
 		// Cross-side play triggers: Rhino rocks anyone who just played;
 		// Crocodile volleys when the enemy plays their last pet.
-		for seat := range sides {
+		for _, seat := range seatOrder {
 			if !newlyPlayed[seat] {
 				continue
 			}
-			for other, os := range sides {
+			for _, other := range seatOrder {
+				os := sides[other]
 				if other == seat {
 					continue
 				}
@@ -644,6 +658,12 @@ func (g *Game) resolveBattle() {
 			res.Trophies = 2
 		}
 		g.Players[winner].Trophies += res.Trophies
+		// Priority token: the winner hands it to the other player; a loser
+		// who held it keeps it; a draw leaves it put. (Two-player rule; the
+		// "other player" is unambiguous only at n == 2.)
+		if winner == g.PrioritySeat {
+			g.PrioritySeat = (winner + 1) % n
+		}
 	}
 
 	g.Battle = res