Task Dependency Resolution (Topological Sort)

Requirements A Task is defined by a string id and a list of dependency ids: The output must include all transitive dependencies of the requested tasks, arranged so that each task appears only after the tasks it depends on. The solution must be correct, efficient on large graphs, and easy to read. Examples (Underlying graph: web:deploy depends on web:test, web:build, web-client:test; web:test depends on web:build; web-client:test depends on web-client:build.)