Add the playable scene loop: boot through mission to reward

Wires every autoload up to a real UI: boot -> profile select/create
-> world map (three mission markers, positioned from data, not
hardcoded pixels) -> mission intro (narrative from data/missions/,
a new data type with its own schema) -> rule panel -> exercise host
-> one of the three exercise type scenes -> feedback panel -> reward
screen -> back to the map.

exercise_host is the only piece with real orchestration logic: picks
exercises via ExerciseEngine (now fully implemented, validating at
load like make validate-data does), validates answers through the
pure AnswerValidator/DictationAnalyzer, escalates aid over 3 attempts
via AttemptFlow, feeds DifficultyManager so adaptive difficulty is
actually wired in rather than dead code, and records every attempt
through ProgressManager. Every exercise-type scene (multiple_choice,
sentence_correction, dictation) only emits its answer by signal, per
the architecture invariant.

All child-facing text now comes from data/localization/fr.json via
UIText, not hardcoded in scripts or scenes. Getting that right
required extending SchemaValidator to support "additionalProperties"
as a schema (dynamic keys), which also closed a real gap: save.skills
was previously unvalidated against SkillState's actual shape.

16 new headless tests, including two integration tests that instance
exercise_host.tscn directly and drive it by emitting child-scene
signals, stopping short of the final scene transition (which would
tear down the test runner's own tree). Everything that needs a
screen -- layout at different sizes, touch, virtual keyboard, actual
audio playback (no .ogg files exist yet) -- is listed in the new
docs/testing/manual-checklist.md instead of claimed as verified.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

scripts/data/exercise_picker.gd

@@ -0,0 +1,25 @@
+class_name ExercisePicker
+extends RefCounted
+## Choisit un exercice parmi une liste de candidats, sans jamais redonner celui
+## qui vient d'etre traite ("Points durs" du prompt de lancement : une revision
+## tire un autre exercice de la meme regle, jamais celui qui vient d'etre
+## rate). Code pur : le generateur aleatoire est injecte, jamais lu
+## directement.
+
+
+## Retourne null si `candidates` est vide. Si tous les candidats sont exclus
+## (un seul exercice disponible), le redonne : pas d'autre choix possible.
+static func pick(
+    candidates: Array[Dictionary], exclude_id: String, rng: RandomNumberGenerator
+) -> Variant:
+    if candidates.is_empty():
+        return null
+
+    var pool: Array[Dictionary] = []
+    for candidate in candidates:
+        if candidate["id"] != exclude_id:
+            pool.append(candidate)
+    if pool.is_empty():
+        pool = candidates
+
+    return pool[rng.randi_range(0, pool.size() - 1)]

scripts/data/exercise_picker.gd.uid

@@ -0,0 +1 @@
+uid://deb67kr6jsoe

scripts/data/schema_validator.gd

@@ -81,8 +81,13 @@ static func _validate_object(
     for key: String in value.keys():
         if properties.has(key):
             _validate_node(value[key], properties[key], "%s.%s" % [path, key], errors)
-        elif additional_allowed == false:
+        elif typeof(additional_allowed) == TYPE_BOOL and additional_allowed == false:
             errors.append("%s : propriete inattendue '%s'" % [path, key])
+        elif typeof(additional_allowed) == TYPE_DICTIONARY:
+            # additionalProperties est lui-meme un schema : toute cle non
+            # listee dans "properties" doit s'y conformer (cles dynamiques,
+            # ex. une competence par skill_id dans une sauvegarde).
+            _validate_node(value[key], additional_allowed, "%s.%s" % [path, key], errors)
 
 
 static func _validate_array(

scripts/data/ui_text.gd

@@ -0,0 +1,27 @@
+class_name UIText
+extends RefCounted
+## Textes d'interface destines a l'enfant, charges depuis
+## data/localization/fr.json : jamais en dur dans les scripts ou les scenes
+## (voir CLAUDE.md, Conventions de code).
+
+const LOCALIZATION_PATH := "res://data/localization/fr.json"
+
+static var _cache: Dictionary = {}
+
+
+static func get_text(key: String) -> String:
+    if _cache.is_empty():
+        _load()
+    if not _cache.has(key):
+        push_error("Cle de traduction manquante : %s" % key)
+        return key
+    return _cache[key]
+
+
+static func _load() -> void:
+    var file := FileAccess.open(LOCALIZATION_PATH, FileAccess.READ)
+    if file == null:
+        push_error("Fichier de traduction introuvable : %s" % LOCALIZATION_PATH)
+        return
+    var parsed: Variant = JSON.parse_string(file.get_as_text())
+    _cache = parsed if typeof(parsed) == TYPE_DICTIONARY else {}

scripts/data/ui_text.gd.uid

@@ -0,0 +1 @@
+uid://ccyua7ei6gssv

scripts/data/validate_data_cli.gd

@@ -12,6 +12,8 @@ func _init() -> void:
     checked += _validate_simple_dir("res://data/curriculum", "curriculum", failures)
     checked += _validate_dictations("res://data/dictations", failures)
     checked += _validate_exercises("res://data/exercises", failures)
+    checked += _validate_missions("res://data/missions", failures)
+    checked += _validate_simple_dir("res://data/localization", "localization", failures)
 
     if failures.is_empty():
         print("validate-data : %d fichier(s) JSON valide(s)" % checked)
@@ -43,6 +45,30 @@ func _validate_dictations(dir_path: String, failures: Array[String]) -> int:
     return count
 
 
+func _validate_missions(dir_path: String, failures: Array[String]) -> int:
+    var known_rule_ids: Array[String] = []
+    for path in DataLoader.find_json_files("res://data/rules"):
+        var rule: Variant = DataLoader.read_json(path)
+        if typeof(rule) == TYPE_DICTIONARY and rule.has("rule_id"):
+            known_rule_ids.append(rule["rule_id"])
+
+    var count := 0
+    for path in DataLoader.find_json_files(dir_path):
+        count += 1
+        var schema_errors := DataLoader.validate_file(path, "mission")
+        failures.append_array(schema_errors)
+        if not schema_errors.is_empty():
+            continue
+        var data: Dictionary = DataLoader.read_json(path)
+        if not known_rule_ids.has(data["rule_id"]):
+            var message := (
+                "%s : rule_id '%s' ne correspond a aucune regle de data/rules"
+                % [path, data["rule_id"]]
+            )
+            failures.append(message)
+    return count
+
+
 func _validate_exercises(dir_path: String, failures: Array[String]) -> int:
     var count := 0
     for path in DataLoader.find_json_files(dir_path):

scripts/profiles/progress_updates.gd

@@ -58,3 +58,14 @@ static func unlock_region(save_data: Dictionary, region_id: String) -> Dictionar
         regions.append(region_id)
     updated["unlocked_regions"] = regions
     return updated
+
+
+## Les recompenses valorisent l'effort et la progression, jamais la vitesse
+## (cahier des charges §2, principe 6) : un nombre fixe d'etoiles par mission
+## terminee, quel que soit le temps pris ou le nombre d'aides utilisees.
+static func add_stars(save_data: Dictionary, amount: int) -> Dictionary:
+    var updated: Dictionary = save_data.duplicate(true)
+    var rewards: Dictionary = updated["rewards"].duplicate(true)
+    rewards["stars"] = int(rewards["stars"]) + amount
+    updated["rewards"] = rewards
+    return updated