Function validateDependencyGraph

Workflows exports - Workflow engine with parallel execution Split from index.ts for file size compliance (Issue #285)

validateDependencyGraph(workflow: WorkflowDefinition): Result<void, ParseError>
Validates the dependency graph of a workflow. Checks for:
- Duplicate step IDs
- Missing step references
- Circular dependencies
Parameters
- workflow: WorkflowDefinition
  The workflow definition to validate
Returns Result<void, ParseError>
Result with void or ParseError
- Defined in packages/nexus-agents/src/workflows/dependency-graph.ts:273