A Commander/Brawl deck can now have two commanders when their abilities
allow it. Partner abilities are parsed from oracle text (Scryfall's keyword
list files every "Partner—Survivors"-style variant under plain "Partner"),
and a second search box offers only cards that can pair with the commander.
The legality check accepts a valid pair and checks color identity against
both; suggestions and decklist import/export handle both commanders.
Closes#4
Garrett Mills
bfad4c1f27