--- "effect": patch --- added graph set operations for combining and comparing graphs - `Graph.make` - creates a graph constructor for a dynamically selected graph kind - `Graph.compose` - composition of two graphs, merging nodes by identity - `Graph.intersection` - intersection of two graphs, keeping only common nodes and edges - `Graph.difference` - difference of two graphs, removing edges present in the second graph - `Graph.symmetricDifference` - symmetric difference of two graphs, keeping edges present in exactly one graph