What this changes

The monthly credit overdraft invoice shows a hardcoded line item text: "Credit Overdraft".

This PR changes it to use the title of the configured credit overdraft product. If the title is empty, it falls back to "Credit Overdraft" as before.

Why

The finance team wants a proper service description on the invoice line. The token purchase invoice already prints the product title (Stripe uses the product name as the line text). With this change, the overdraft invoice reads from the same field. Operators can then set the wording once, in the product config.

How it works

• Init already loads the overdraft product for its price. It now also stores the product title.
• GenerateForCredits uses that title as the invoice item name.
• The item name becomes the Stripe line description in CreateInProvider.

Notes

• No change if the product has no title: the line still says "Credit Overdraft".
• Invoice reconciliation is not affected. It matches items by type, not by name.

Deploy order

A downstream consumer matches invoice line names against the literal string "Credit Overdraft", so it must be updated first:

1. Merge and deploy pixxelhq/business-data-syncer#28. It makes the Planhat sales sync match overdraft items by type instead of name.
2. Then merge and deploy this PR.
3. Then update the token product title in configs.