Fix bugs around AI opponents.

internal/game/golden45_test.go

@@ -156,6 +156,23 @@ func TestManateeSelfRockFatalStillAddsApples(t *testing.T) {
 	}
 }
 
+// A player whose only in-play pet faints to its own play effect (Manatee's
+// self-rock) still wins if it has pets left in its deck and the opponent has
+// none. The battle loop breaks the instant the opponent runs out — before the
+// survivor's next pet is revealed — so the winner must be decided by who can
+// still field a pet, not by who happens to have one in play at that instant.
+func TestSelfFaintWithReserveStillWins(t *testing.T) {
+	g, _, _ := testGame(t)
+	g.RollDie = func() int { return 2 } // 2 rocks = 4 damage, fatal to the 3-power Manatee
+	res := forceBattle(t, g,
+		[]Card{g.goldenPet(t, "Manatee"), g.pet("Reserve", 5)},
+		[]Card{g.newApple()}, // opponent has only food — no pet, ever
+	)
+	if res.WinnerSeat != 0 {
+		t.Fatalf("seat 0 should win with a reserve pet vs an all-food deck, got winner %d", res.WinnerSeat)
+	}
+}
+
 // Poison Dart Frog, once set aside, throws rocks each time a Bee is played.
 func TestPoisonDartFrogBeeRocks(t *testing.T) {
 	g, _, _ := testGame(t)