Regenerate drifted repository artifacts

[gunbai-bot]

Summary

• remove the undeclared cross_module_mechanism_weighting.py negation from generated .gitignore
• refresh the representation-minimization plan projection after Map was renamed to PartialFunction

Verification

• built the current checkout's release gunbc locally
• ran gunbc run --source-root dag --source-root src/v2 --entry dag/tools/generated_artifact_gate.dag --function main_wet locally twice
• first pass left the full generated artifact registry byte-identical to the commit
• second pass also left the working tree clean, establishing the generator fixed point
• pre-push cargo fmt --all --check