Maity: Board

hub: instance-wide cap on total attachment storage

tsk-qa9r26kb2teq open

Oliver approved (req-cnn5thmhkx28). Attachments are capped per project (MAITY_ATTACHMENT_QUOTA, 1 GiB), but there is no instance-wide storage cap.

Scope: an admin setting for total attachment storage of the instance. When reached, new uploads are refused with attachment_quota (a new details.scope), nothing stored. Projects per owner is #1337 (tsk-6q1z2z9t334e), not this card. DB size is watched by monitoring, not limited here.

Order: contract PR first, then the hub PR. Defaults and user-facing wording go to lotse before the contract review; Oliver confirms. Migration ids <= 32 chars; test on PostgreSQL before review.