v27.4: Fix blank Collection/Decks pages — API response unwrapping
- collection.ts: unwrap {items} -> cards, map camelCase params (pageSize, sortField, etc)
- decks.ts: unwrap {decks} from listDecks, {cards} from getDeckCards, normalize field names (commander_name->commander, total_cards->card_count, role_tag->category)
- decks.ts: transform getDeckAnalysis from backend shape (counts_by_type, color_pips) to frontend shape (card_count, land_count, type_distribution, etc)
- types: SetInfo.card_count now optional (backend doesn't provide it)
- Installer now bundles pre-built React dist/ as fallback