The shard grouping default is one shard per project

The default grouping of UD-S2 is project; hash:<n> and user groupings are settings (UR-05).

Provenance: technical default selected by the coordinator, described in the original conversation at line 5525 (2026-10-01), not an option accepted by the user in answer 5469. The later storage/durability approval at 5760 does not retrospectively turn this selection into a direct user answer.