enforce_deck_ratios can return the same card name under multiple
categories (e.g. Teferi's Protection in both protection + synergy).
all_card_names had no cross-category dedup, so get_cards_by_names
returned duplicate CardEntry objects that then failed the singleton
validator in CommanderDeck.
Fix: build all_card_names with dict.fromkeys() across all categories
so each name appears exactly once. Also deduplicate after Scryfall
lookup by name as a second safety net.
KoalaTrapLord
88f1022d0e