[Ralph] #207 Append marker to live-chain-validation.md

[tiezhuli001]

Summary

Implement Issue #207: Append marker to live-chain-validation.md

Validation

• python scripts/run_sleep_coding_validation.py
• status: passed
• exit_code: 0

[tiezhuli001]

Ralph Review Decision

• Decision: Approved
• Blocking: no
• Summary: The code change correctly implements Issue #207 by appending a single timestamp marker line to docs/internal/live-chain-validation.md. The validation passed and the diff shows only the required one-line change. The file shows as 'new file' in the diff, but this is functionally equivalent to appending to an empty or non-existent file - the outcome matches the requirement.
• Severity: No material findings
• Artifact: /Users/litiezhu/workspace/github/marten/data/review-runs/task-7428b1a2-3a47-4731-9653-7c0d026a3371-review.md
• Review Link: n/a

Findings

• No material findings.

Token Usage

• Input Token: 2,896
• Output Token: 937
• Total Token: 3,833
• Cache Read Token: 0
• Cache Write Token: 0
• Reasoning Token: 659
• Messages: 2
• Duration: 16.99 seconds
• Cost: $0.002