Build or refresh the local Scryfall card database (.mtg/database/cards.sqlite) that the MTG deckbuilding skills read from instead of calling the Scryfall API. Use this skill when the user wants to set up, build, refresh, or update their local MTG card data, when card prices or sets seem out of date, or as the one-time setup step before building or upgrading Commander/EDH or MTG Arena Standard decks. The deck skills also invoke this automatically when the database is missing or stale. It downloads Scryfall's "Default Cards" bulk file, collapses it to one row per unique card (cheapest EUR/USD price, Arena availability, rarity, legalities, Game Changer flag, EDHREC rank), an…
