Addresses CI lint feedback on PR #1391. No behavior change.
- Split `import json, sys` into separate lines (E401)
- Split chained `print(...); sys.exit(1)` into two lines (E702, two occurrences)
- Split inline `if ts: stamps.append(ts)` into two lines (E701)
Verified: `ruff check tools/render_jsonl.py` reports "All checks passed!"
Tool still renders correctly (3 turns from a real JSONL test, identical output to pre-fix).
MillaJ
921ff5a6fa