auto-report missed payments of last month

[qbe]

at the beginning of a month, notify the metalab board which users missed a payment or picked up a bounce,
include the following data in the list of users

• username, email
• last payment method
• balance
• balance change this month

[qbe]

ignore users that

• have a positive balance
• have "cash" as their last payment method and are above a certain threshold balance ?
• have a bank collection mode less than monthly and don't have any unexplained negative balance