Port evolution, Rare Candy, evolution stones and vitamins

Pokémon that levelled up evolve after a won battle, following
EvolveAfterBattle's checks over the ROM's evolution bytes, with the
evolution screen that B can stop and move learning outside battle. The pack
uses Rare Candy, stones (with ABLE/NOT ABLE labels) and vitamins, and its
pocket tabs now sit in their own row.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/game/battle/battle.ts

@@ -126,7 +126,13 @@ export type BattleAction =
   /** PACK: use the item in this slot of its pocket (only Balls so far). */
   | { action: "item"; item: number; slot: number };
 export type BattleInput = number | string | BattleAction | undefined;
-export type BattleOutcome = { result: number; prizeMoney?: number };
+/** wBattleResult, the prize money and wEvolvableFlags (a bit per party
+ * index that levelled up). */
+export type BattleOutcome = {
+  result: number;
+  prizeMoney?: number;
+  evolvable?: number;
+};
 
 export interface BattleTrainer {
   name: string;
@@ -406,6 +412,9 @@ export class Battle {
   numFleeAttempts = 0;
   /** wBattleParticipantsNotFainted, which shares the experience. */
   participants = 0;
+  /** wEvolvableFlags: party members that levelled up, which
+   * EvolveAfterBattle checks after a win. */
+  private evolvable = 0;
   /** wBattleParticipantsIncludingFainted, which revives consult. */
   private participantsAll = 0;
   /** wEnemyMonBaseStats: five base stats, catch rate and base exp. */
@@ -790,11 +799,11 @@ export class Battle {
       const prizeMoney = trainer.reward * (amuletCoin ? 2 : 1);
       this.numbers[RAM.battleReward] = prizeMoney;
       yield* this.say(BATTLE.GotMoneyForWinningText);
-      return { result: this.battleResult, prizeMoney };
+      return { result: this.battleResult, prizeMoney, evolvable: this.evolvable };
     }
     if (trainer && this.options.canLose && trainer.lossText)
       yield* this.say(trainer.lossText);
-    return { result: this.battleResult };
+    return { result: this.battleResult, evolvable: this.evolvable };
   }
 
   private *battleTurn(): Gen {
@@ -3503,6 +3512,7 @@ export class Battle {
         values: [mon.stats[1], mon.stats[2], mon.stats[4], mon.stats[5], mon.stats[3]],
       };
       for (let level = oldLevel + 1; level <= newLevel; level++) yield* this.learnLevelMoves(mon, index, level);
+      this.evolvable |= 1 << index;
     }
     this.resetBattleParticipants();
   }