Task 159: Cross-Episode Counterfactual Analysis Section

Status: DONE

Motivation

CLAUDE.md directs: "Explore IF scenarios — what would happen if characters had made different decisions?"

Per-episode reports contain local counterfactuals (e.g., EP05's no-flyby analysis), but the cross-episode summary report has no cross-episode counterfactual section comparing alternative mission profiles. For example:

• What if Kestrel had taken a direct brachistochrone from Mars to Earth?
• What if there was no Enceladus resupply?
• What if the ship had bypassed Titania?

These mission-level "what if" scenarios deepen the analysis by putting the actual route in perspective.

Scope

1. Add a "反事実分析: もし別のルートを選んでいたら？" section to cross-episode.json
2. Analyze 3-4 alternative mission profiles:

- Direct Mars→Earth brachistochrone (no intermediate stops)

- No Enceladus resupply scenario

- Direct Saturn→Earth (bypass Titania/Uranus)

1. Compare ΔV, travel time, propellant requirements with actual route
2. Include a bar chart comparing scenarios

Dependencies

• Cross-episode analysis (DONE)
• Propellant budget section (DONE, with new mass timeline from Task 158)
• EP05 counterfactual (direct brachistochrone, DONE in EP05 detail page)