Module visualization 

DAG visualization for workflow monitoring.

Supports multiple output formats:

• DOT (Graphviz) - full-featured graph rendering
• Mermaid - browser-friendly diagrams
• JSON - structured data for programmatic consumption
• SVG - self-contained vector graphics with grid-based layout
• ASCII - terminal-friendly text rendering
• PlantUML - UML-style activity diagrams

Structs

DagVisualizer

DAG visualizer.

ExecutionVisualization

Workflow execution visualization data.

GanttTask

Gantt chart task representation.

VisualizationConfig

Visualization configuration.

Enums

GraphFormat

Graph output format.

TaskVisualStatus

Visual status for a task node, used for coloring.