Franchise Reservation Hold

A 15-minute reservation hold on 3v3 S1 franchise picks ends the owner race-claim - two people can never grab the same city.

Added

15-minute reservation hold the moment you tap a franchise - locks it to your session through checkout

Other owners see the city as 'On hold' in the picker until your hold expires

Changed

Race-claim race condition between simultaneous checkouts closed

Auth-redirect now preserves the franchise query param so you land back on your pick