Detect Cycles in Trading Dependencies

AKUNA CAPITAL models relationships between trading components as a directed dependency graph. An edge A -> B means component A must be processed before component B.

Implement has_cycle(graph) to determine whether the directed graph contains a cycle. A cycle means that no valid processing order exists because at least one component depends, directly or indirectly, on itself.

Formal Specification

• Input graph: a dictionary mapping each component name to a list of components it directly depends on.
• Every component name is a string. A referenced component may be absent as a key, and should still be treated as a valid node with no outgoing edges.
• Output: return True if the graph contains at least one directed cycle; otherwise return False.
• The graph may be disconnected and may contain self-loops.