- C1: Invalid port parameter values now produce MACRO errors instead of silently falling back to Port.L. _clone_and_substitute_edge returns errors like _clone_and_substitute_node already does. - I1: Leaked @ret edges from failed inner macro expansions are now filtered out to prevent spurious cascading errors at outer scope. - I2/M3: Added tests for invalid port values and bare @ret with only named outputs. - M1: Fixed test-requirements.md file references to match actual names. - M2: lower.py edge qualification now uses replace() to preserve all fields (port_explicit, ctx_override) instead of constructing new IREdge.