Task 457: Add Radiation Shield and Trim-Thrust Charts to EP02

Status: DONE

Summary

EP02 has rich numerical analysis (Jupiter radiation shield scenarios, trim-thrust 2-phase model comparisons) but only 1 bar chart and 1 timeseries chart — much less visual than EP03 (2 bar + 3 timeseries after Task 454). Adding targeted charts to EP02 will make the Jupiter escape and transit analysis more intuitive.

Plan

1. Jupiter radiation shield survival chart (timeseries): Show accumulated dose vs distance for different radial velocity scenarios (7, 20, 60 km/s) with the shield budget line. Visualizes why active acceleration is needed to survive.
2. Trim-thrust 2-phase model comparison (bar chart): Show transit time vs arrival v∞ for the 4 scenarios in the table (accel-only, equal split, extended, ballistic). Makes the tradeoff between transit time and arrival speed visual.
3. Content validation tests: Add TDD tests for new chart data.

Impact

• Makes EP02's radiation and transit analysis accessible through visualization
• Follows CLAUDE.md guidance: "More figures are better than fewer"
• Brings EP02 visual density closer to EP03's level