fix: delegate file discipline, verify loop limits, artifact reading ban

[FL4TLiN3]

Summary

• Delegate meta instruction (@perstack/runtime): Add file creation discipline — prefer editing over creating, no proactive documentation files
• verify-test: Explicit ban on reading/reviewing produced artifacts — only command outputs matter
• build loop: Validate CONTINUE feedback (only hard signal failures are valid loop reasons), max 3 iterations to prevent infinite loops
• Bump create-expert to 1.0.19

Context

Production run showed:

1. Delegates creating new files on each iteration instead of editing existing ones → workspace filled with garbage
2. verify-test reading artifact contents and doing quality review (e.g., "use Random instead of Date") instead of executing hard signal commands
3. build blindly looping on soft opinion feedback, never converging

Test plan

• Run create-expert and verify workspace doesn't accumulate stale files across iterations
• Confirm verify-test only reports command results, not artifact content opinions
• Verify build loop stops after 3 iterations if signals don't pass
• Verify build rejects soft opinion CONTINUE feedback

🤖 Generated with Claude Code