Port the options screen

OPTION in the start menu runs _Option with the ROM's labels and settings,
OptionsControl's cursor wrapping and each option's bit handling. The four
option bytes live in the script state and saves, defaulting to
DefaultOptions. The battle style now decides whether a trainer's next
Pokémon brings an offer to switch, and the menu account whether the start
menu describes its items; the other settings are kept for later.

Closes #24

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

docs/ARCHITECTURE.md

@@ -87,7 +87,8 @@ callee's ROM script in the event interpreter on the same draft. The world
 keeps the card on screen (`world.pokegear`) during the call's texts.
 `scripts/mom.ts` runs `BankOfMom` as a special; its amount box is a
 `mombank` effect answered with buttons in the same way, and so are the
-pages of `scripts/trainer-card.ts`. The world refreshes the card's play
+pages of `scripts/trainer-card.ts` and the screen of `scripts/options.ts`,
+whose option bytes live in the script state. The world refreshes the card's play
 time, colon and badge step every tick; `world/game-time.ts` is the play
 time (`wGameTime`), which the world advances two frames per tick.