Quirk suggestion: Citi Commercial

Perhaps surprisingly, this differs to #611. From https://home.cards.citidirect.com/CommercialCard/applyforcard/invpasscode/invpc:

> Password is case sensitive and:
>
> - Should have 8 to 18 characters
> - At least one letter is required
> - Must contain at least a number
> - Cannot contain more than 1 consecutive identical characters
> - User name and password cannot be same

Review the related issue #611 and the Citi Commercial invitation-passcode page linked in this issue, including the listed password constraints and screenshot. Done means the repository records Citi Commercial’s case sensitivity, length, character, repetition, and username rules accurately and consistently with the existing resource format.

Written by the indexing model from the issue text.