Two sports, two career-making scrambles this week. Football had its first $1 billion day in a free agency bonanza. New salary cap rules push the teams to spend more. A lot more. Middling players have snagged fortunes. College basketball players can only dream of such money as they take the stage for March Madness’ Selection Sunday, kicking off the tournament that launched a thousand office betting pools — and NBA careers, of course. Break out those brackets — play begins Tuesday.