Phase "score et récompenses" of the post-0.1.0 plan (user feedback:
wants a more game-like experience with scoring and rewards).
- MissionScoring: 1-3 stars from how each exercise was solved (never
speed; a finished mission always gives at least one star).
- Save schema v2: mission_results (best/last stars, completions) with a
v1->v2 migration that keeps existing stars and items.
- Total only grows by the improvement over a mission's best score.
- Data-driven collection (data/rewards, reward_item schema, validated
incl. mission cross-check) unlocked by RewardRules.
- Reward screen, collection screen, stars on the world map.
- Version 0.2.0.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Denis Defolie