SharedWorkflowGraph
    hash        WorkflowGraphReference
    graph       (WorkflowGraph FileReference SqlBackendKey) -- UserId
    Primary     hash

WorkflowDefinition
    graph       SharedWorkflowGraphId
    scope       WorkflowScope'
    name        WorkflowDefinitionName 
    instanceCategory WorkflowInstanceCategory Maybe
    UniqueWorkflowDefinition name scope

WorkflowDefinitionDescription
    definition  WorkflowDefinitionId
    language    Lang
    title       Text
    description StoredMarkup Maybe
    UniqueWorkflowDefinitionDescription definition language

WorkflowDefinitionInstanceDescription
    definition  WorkflowDefinitionId
    language    Lang
    title       Text
    description StoredMarkup Maybe
    UniqueWorkflowDefinitionInstanceDescription definition language

WorkflowInstance
    definition  WorkflowDefinitionId Maybe
    graph       SharedWorkflowGraphId
    scope       (WorkflowScope TermIdentifier SchoolShorthand SqlBackendKey)  -- TermId, SchoolId, CourseId
    name        WorkflowInstanceName
    category    WorkflowInstanceCategory Maybe
    UniqueWorkflowInstance name scope
    
WorkflowInstanceDescription
    instance    WorkflowInstanceId
    language    Lang
    title       Text
    description StoredMarkup Maybe
    UniqueWorkflowInstanceDescription instance language

WorkflowWorkflow
    instance    WorkflowInstanceId Maybe
    scope       (WorkflowScope TermIdentifier SchoolShorthand SqlBackendKey)  -- TermId, SchoolId, CourseId
    graph       SharedWorkflowGraphId
    state       (WorkflowState FileReference SqlBackendKey)  -- UserId