Add mission scoring, rewards collection and save schema v2

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>

data/localization/fr.json

@@ -45,7 +45,24 @@
   "dictation.input_placeholder": "Écris ici...",
   "dictation.replay_button": "Réécouter",
   "dictation.provisional_audio_badge": "Voix provisoire",
-  "reward_screen.title": "Mission réussie !",
+  "reward_screen.title": "Mission terminée !",
   "reward_screen.stars_label": "Étoiles gagnées :",
+  "reward_screen.message_1": "Chaque essai te fait progresser. Tu peux rejouer pour gagner plus d'étoiles !",
+  "reward_screen.message_2": "Bien joué ! Tu as trouvé toutes les réponses.",
+  "reward_screen.message_3": "Parfait ! Tu as tout réussi du premier coup.",
+  "reward_screen.record_label": "Nouveau record pour cette mission !",
+  "reward_screen.total_label": "Total d'étoiles :",
+  "reward_screen.new_items_label": "Nouveaux objets dans ta collection :",
+  "reward_screen.collection_button": "Voir ma collection",
+  "collection.title": "Ma collection",
+  "collection.progress_label": "Objets trouvés :",
+  "collection.locked_title": "Objet mystère",
+  "collection.unlock_total_stars": "À débloquer avec %d étoiles au total",
+  "collection.unlock_mission_stars": "À débloquer avec %d étoiles à la mission « %s »",
+  "collection.back_button": "Retour à la carte",
+  "collection.owned_marker": "Trouvé",
+  "world_map.total_stars_label": "Total d'étoiles :",
+  "world_map.mission_stars_label": "Étoiles :",
+  "world_map.collection_button": "Ma collection",
   "reward_screen.continue_button": "Retour à la carte"
 }

data/rewards/item_carte_ancienne.json

@@ -0,0 +1,10 @@
+{
+  "item_id": "item_carte_ancienne",
+  "title": "Carte ancienne",
+  "description": "Une vieille carte qui montre des lieux que personne n'a encore visités.",
+  "unlock": {
+    "type": "total_stars",
+    "count": 15
+  },
+  "review_status": "draft"
+}

data/rewards/item_cle_argentee.json

@@ -0,0 +1,10 @@
+{
+  "item_id": "item_cle_argentee",
+  "title": "Clé argentée",
+  "description": "Elle ouvre la porte d'un secret caché au fond de la forêt.",
+  "unlock": {
+    "type": "total_stars",
+    "count": 30
+  },
+  "review_status": "draft"
+}

data/rewards/item_couronne_feuilles.json

@@ -0,0 +1,10 @@
+{
+  "item_id": "item_couronne_feuilles",
+  "title": "Couronne de feuilles",
+  "description": "Tressée avec les feuilles de la forêt des accords.",
+  "unlock": {
+    "type": "total_stars",
+    "count": 22
+  },
+  "review_status": "draft"
+}

data/rewards/item_cristal_echo.json

@@ -0,0 +1,10 @@
+{
+  "item_id": "item_cristal_echo",
+  "title": "Cristal d'écho",
+  "description": "Il répète en chantant toutes les phrases bien écrites.",
+  "unlock": {
+    "type": "total_stars",
+    "count": 45
+  },
+  "review_status": "draft"
+}

data/rewards/item_graine_magique.json

@@ -0,0 +1,10 @@
+{
+  "item_id": "item_graine_magique",
+  "title": "Graine magique",
+  "description": "Une petite graine qui brille. Elle attend la bonne forêt pour pousser.",
+  "unlock": {
+    "type": "total_stars",
+    "count": 3
+  },
+  "review_status": "draft"
+}

data/rewards/item_lanterne_foret.json

@@ -0,0 +1,10 @@
+{
+  "item_id": "item_lanterne_foret",
+  "title": "Lanterne de la forêt",
+  "description": "Elle éclaire les chemins quand la nuit tombe sur les mots.",
+  "unlock": {
+    "type": "total_stars",
+    "count": 10
+  },
+  "review_status": "draft"
+}

data/rewards/item_plume_doree.json

@@ -0,0 +1,10 @@
+{
+  "item_id": "item_plume_doree",
+  "title": "Plume dorée",
+  "description": "Une plume tombée de l'aile de Plume, le hibou guide.",
+  "unlock": {
+    "type": "total_stars",
+    "count": 6
+  },
+  "review_status": "draft"
+}

data/rewards/item_trophee_clairiere.json

@@ -0,0 +1,11 @@
+{
+  "item_id": "item_trophee_clairiere",
+  "title": "Trophée de la clairière",
+  "description": "L'écho de la clairière chante ton nom : tu as tout réussi sans aide.",
+  "unlock": {
+    "type": "mission_stars",
+    "count": 3,
+    "mission_id": "mission_03_clairiere_echo"
+  },
+  "review_status": "draft"
+}

data/rewards/item_trophee_pont.json

@@ -0,0 +1,11 @@
+{
+  "item_id": "item_trophee_pont",
+  "title": "Trophée du pont",
+  "description": "Le pont des phrases brille grâce à toi : tu as tout réussi sans aide.",
+  "unlock": {
+    "type": "mission_stars",
+    "count": 3,
+    "mission_id": "mission_02_pont_des_phrases"
+  },
+  "review_status": "draft"
+}

data/rewards/item_trophee_pre.json

@@ -0,0 +1,11 @@
+{
+  "item_id": "item_trophee_pre",
+  "title": "Trophée du pré",
+  "description": "Les lutins t'offrent ce trophée : tu as tout réussi sans aide au pré des petits mots.",
+  "unlock": {
+    "type": "mission_stars",
+    "count": 3,
+    "mission_id": "mission_01_pre_des_mots"
+  },
+  "review_status": "draft"
+}

data/schemas/reward_item.schema.json

@@ -0,0 +1,21 @@
+{
+  "type": "object",
+  "required": ["item_id", "title", "description", "unlock", "review_status"],
+  "additionalProperties": false,
+  "properties": {
+    "item_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" },
+    "title": { "type": "string", "minLength": 1 },
+    "description": { "type": "string", "minLength": 1 },
+    "unlock": {
+      "type": "object",
+      "required": ["type", "count"],
+      "additionalProperties": false,
+      "properties": {
+        "type": { "type": "string", "enum": ["total_stars", "mission_stars"] },
+        "count": { "type": "integer", "minimum": 1 },
+        "mission_id": { "type": "string", "pattern": "^[a-z][a-z0-9_]*$" }
+      }
+    },
+    "review_status": { "type": "string", "enum": ["draft", "validated"] }
+  }
+}

data/schemas/save.schema.json

@@ -8,6 +8,7 @@
     "session_count",
     "unlocked_regions",
     "skills",
+    "mission_results",
     "rewards"
   ],
   "additionalProperties": false,
@@ -48,6 +49,19 @@
         }
       }
     },
+    "mission_results": {
+      "type": "object",
+      "additionalProperties": {
+        "type": "object",
+        "required": ["best_stars", "last_stars", "completions"],
+        "additionalProperties": false,
+        "properties": {
+          "best_stars": { "type": "integer", "minimum": 1, "maximum": 3 },
+          "last_stars": { "type": "integer", "minimum": 1, "maximum": 3 },
+          "completions": { "type": "integer", "minimum": 1 }
+        }
+      }
+    },
     "rewards": {
       "type": "object",
       "required": ["stars", "items"],