Function assert_can_delete_glw_data 

pub async fn assert_can_delete_glw_data(
    db: &SqlitePool,
    current_user: Uuid,
    glw_data_id: Uuid,
) -> Result<GlwDataRow, Error>

Permission gate for deleting a GLW data row. Personal: must be the owner. Group: must be an owner of the group.

The FK saved_renders.glw_data_id is ON DELETE RESTRICT, so a row with at least one referencing render will fail the DELETE with a SQLite constraint violation; the route handler maps that to a human-readable error.

Errors

Returns Error::Forbidden if the user lacks delete permission; Error::NotFound if the row does not exist.