- hasCycles(): uses graphology-dag.hasCycle() as fast boolean check - findCycles(): SCC pre-check + custom 3-color DFS for cycle path extraction - topologicalOrder(): graphology-dag.topologicalSort + CircularDependencyError on cycle - dependencies/dependents: inNeighbors/outNeighbors with TaskNotFoundError - taskCount(): graph.order, getTask(): node attributes or undefined - 45 unit tests covering all acceptance criteria