Task 383: Ship Kestrel ギリギリ一覧 Margin Gauge

Status: DONE

Summary

The ship-kestrel report has a "ギリギリ一覧" section listing 7 critical margins across all episodes as prose bullet points. Add a margin-gauge component to visualize actual vs limit values at a glance.

Rationale

• CLAUDE.md: margin visualization, gauge/bar charts for limit proximity
• The data is already in the report text, just needs visual treatment