Finish the opening milestone's switching, items and acceptance run

- Decode evolution lists from the ROM; all 251 match the pinned PRET source.
- Compare CalcMonStats and CalcExpAtLevel against the original routines in
  the reference emulator.
- Add a continuous opening playthrough from the intro to the catching
  tutorial, reloading a JSON save after every stage.
- Port player switching in battle: the PKMN menu, forced choices after a
  faint, Shift mode's offer and double faints, with the original texts.
- Port HP and status healing items in battle through the ROM's ItemEffects,
  HealingHPAmounts and StatusHealingActions tables.
- Add the battle party menu and the Items pocket to the UI.

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

scripts/check-reference.mjs

@@ -188,6 +188,7 @@ const ramNames = {
   callerContact: "wCallerContact",
   surfingPlayerState: "wSurfingPlayerState",
   strengthSpecies: "wStrengthSpecies",
+  curHPAnimDeltaHP: "wCurHPAnimDeltaHP",
   moneyTemp: "hMoneyTemp",
 };
 const profile = readFileSync("src/game/rom/profile.ts", "utf8");