DawnAircraftDesignOptimization constraints:
1) Candidate file is `scripts/init.py` and must output `submission.json`.
2) `submission.json` must be a JSON object with numeric keys:
   - wing_span_m
   - wing_area_m2
   - fuselage_length_m
   - fuselage_diameter_m
   - motor_power_kw
   - battery_mass_kg
   - cruise_speed_mps
3) All design values must stay within bounds in `references/mission_config.json`.
4) Feasibility requires all margins >= 0:
   - takeoff distance, stall speed, cruise lift, structural stress,
     endurance energy, cruise power headroom, wing loading,
     fuselage fineness ratio, and aspect-ratio bounds.
5) Objective: minimize total_mass_kg under constraints.
