Two operations, selected by op:

• { "op": "create" }: backs up the project now. Deduplicated: when the current content matches a stored snapshot, nothing is uploaded and the response has deduped: true. Returns 200 { object: "backup_created", deduped }.
• { "op": "restore", "backupId": "…" }: restores that backup as a new project in the caller's shop. It never overwrites the current project, so no confirmation is required. Returns 201 { object: "project_restored", newProjectId }.

Neither operation is destructive to existing content. The backup id must belong to this project (404 otherwise).

Required scope: project:manage