Task 476: Add Charts to EP01 Remaining Explorations

Status: DONE

Summary

EP01 has 3 charts for 7 explorations (ratio 0.43, lowest among episodes). Add 2 charts for the most data-rich explorations without charts:

1. Required thrust chart (exploration-02): 9.8 MN (actual) vs 100 MN (10x) vs 1,574 MN (needed for 72h at 48,000t). Shows the 161x thrust gap at nominal mass.
2. HUD accuracy + Oberth efficiency chart (exploration-04): vis-viva computed 17.92 vs HUD displayed 17.8 km/s (0.67% error), plus Oberth efficiency ratio at different altitudes (ΔV from exploration-05 data overlaps nicely).

Plan

1. Write content validation tests (TDD red)
2. Add 2 bar charts after relevant explorations
3. Verify tests pass (TDD green)
4. Commit

Impact

• Brings EP01 from 3 to 5 bar charts
• Visualizes the thrust gap at nominal mass
• Visualizes the HUD data accuracy and Oberth efficiency