Remove 4 stale patch artifact files that have outlived their purpose:
- patches/nl/*.json - ephemeral natural-language plan records (unknown, patch_create)
- patches/patch_collab-*.branch.json - collab test branch records for branches
that have been merged and had no local residual branch
The self-evolution-agent-orchestration-policy.json patch record is retained
because patch/self-evolution-agent-orchestration-policy branch is still live.