Create a workflow

Scope 1 workflow JSON document, mirroring ZWorkflowDefinition in packages/workflows. The definition is the public source of truth for the builder and API clients. Scope 1 intentionally excludes user-authored if/else branches, webhook actions, schedules, delays, loops, and AI/MCP-assisted creation; future node types extend nodes additively.

Graph rules enforced on every write (400 with invalid_params on violation): node ids are unique across trigger and nodes; every edge references existing node ids; the trigger has at most one outgoing edge; entryNodeId equals trigger.id. Trigger-only drafts (no nodes, no edges) are valid persisted documents. Executability rules (exactly one outgoing trigger edge, acyclic graph, every node reachable from the trigger) are additionally enforced by enable and test with 422 workflow_not_executable.

Slim workflow shape returned by GET /api/v3/workflows. triggerType and surveyId are derived read-only projections of definition.trigger, so list consumers can render and filter without loading full definitions. Serialized dates are ISO 8601 strings.