Add profile and save persistence, wired into the three autoloads

scripts/profiles/: SaveIO handles real file I/O in user://saves (one
file per profile_id, atomic write via temp-file-then-rename, backup
copy before each overwrite, corrupted-main falls back to backup,
schema-invalid content is rejected like corruption). SaveMigration
and SaveFactory are pure; SaveMigration refuses a schema_version it
doesn't recognize (older or newer) rather than guessing. ProgressUpdates
is pure and wires ReviewScheduler/DifficultyManager onto a save's
skills dict, including per-session overdue-review marking.

The three autoloads (SaveManager, ProfileManager, ProgressManager)
stay thin: in-memory current-profile state and orchestration only,
no logic of their own, so the actual behavior lives in the tested
pure/file-IO modules above rather than in untestable glue.

26 new headless tests, including the failure modes called out in the
launch prompt: a truncated .tmp file never corrupts the readable
save, a corrupted main file falls back to its backup, two profiles
never mix (down through the real autoload layer, not just SaveIO),
and an unknown future schema_version is rejected outright.

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

scripts/profiles/progress_updates.gd

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+class_name ProgressUpdates
+extends RefCounted
+## Fonctions pures qui appliquent une tentative d'exercice ou un debut de
+## seance a une sauvegarde (dictionnaire conforme a save.schema.json), en
+## s'appuyant sur ReviewScheduler et DifficultyManager (scripts/pedagogy/).
+## ProgressManager (autoload) est seul responsable d'appeler ces fonctions et
+## de persister le resultat via SaveManager ; l'ecriture sur disque reste
+## groupee en fin de mission (docs/specs/decisions.md, point 7).
+
+
+## attempt : {"skill": String, "success": bool, "hint_used": bool,
+## "exercise_type": String}.
+static func record_attempt(save_data: Dictionary, attempt: Dictionary) -> Dictionary:
+    var updated: Dictionary = save_data.duplicate(true)
+    var skills: Dictionary = updated["skills"]
+    var skill_id: String = attempt["skill"]
+    var skill_state: Dictionary = (
+        skills[skill_id] if skills.has(skill_id) else ReviewScheduler.initial_state()
+    )
+    var current_session: int = updated["session_count"]
+    skills[skill_id] = ReviewScheduler.record_attempt(skill_state, attempt, current_session)
+    updated["skills"] = skills
+    return updated
+
+
+## A appeler une fois en debut de seance, avant toute tentative : incremente
+## session_count et bascule en "a_reviser" les competences "acquise" dont le
+## delai de revision est depasse sans nouvelle pratique.
+static func start_session(save_data: Dictionary) -> Dictionary:
+    var updated: Dictionary = save_data.duplicate(true)
+    updated["session_count"] = int(updated["session_count"]) + 1
+    var current_session: int = updated["session_count"]
+
+    var skills: Dictionary = updated["skills"]
+    var updated_skills: Dictionary = {}
+    for skill_id: String in skills:
+        updated_skills[skill_id] = ReviewScheduler.mark_overdue_as_review(
+            skills[skill_id], current_session
+        )
+    updated["skills"] = updated_skills
+    return updated
+
+
+static func next_difficulty_for_skill(
+    save_data: Dictionary, skill_id: String, current_difficulty: int
+) -> int:
+    var skills: Dictionary = save_data["skills"]
+    if not skills.has(skill_id):
+        return current_difficulty
+    var recent: Array[bool] = skills[skill_id]["recent_results"]
+    return DifficultyManager.next_difficulty(current_difficulty, recent)
+
+
+static func unlock_region(save_data: Dictionary, region_id: String) -> Dictionary:
+    var updated: Dictionary = save_data.duplicate(true)
+    var regions: Array = updated["unlocked_regions"]
+    if not regions.has(region_id):
+        regions.append(region_id)
+    updated["unlocked_regions"] = regions
+    return updated

scripts/profiles/progress_updates.gd.uid

@@ -0,0 +1 @@
+uid://ql1hepqsa81w

scripts/profiles/save_factory.gd

@@ -0,0 +1,17 @@
+class_name SaveFactory
+extends RefCounted
+## Construit une nouvelle sauvegarde vide pour un profil, conforme a
+## data/schemas/save.schema.json. Code pur.
+
+
+static func new_save(profile_id: String, display_name: String, school_level: String) -> Dictionary:
+    return {
+        "schema_version": SaveMigration.CURRENT_SCHEMA_VERSION,
+        "profile_id": profile_id,
+        "display_name": display_name,
+        "school_level": school_level,
+        "session_count": 0,
+        "unlocked_regions": [],
+        "skills": {},
+        "rewards": {"stars": 0, "items": []},
+    }

scripts/profiles/save_factory.gd.uid

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

scripts/profiles/save_io.gd

@@ -0,0 +1,115 @@
+class_name SaveIO
+extends RefCounted
+## Lecture/ecriture des sauvegardes par profil dans user://saves, avec
+## ecriture atomique (fichier temporaire puis remplacement), copie de secours
+## en cas de corruption du fichier principal, et migration de schema a la
+## lecture. Pas pur (touche le systeme de fichiers), mais sans dependance a
+## l'arbre de scenes : testable en headless avec de vrais chemins user://.
+## Un profil ne lit et n'ecrit jamais que son propre fichier (nomme par
+## profile_id) : deux profils ne peuvent pas se melanger.
+
+const SAVE_DIR := "user://saves"
+
+
+static func write(profile_id: String, data: Dictionary) -> bool:
+    DirAccess.make_dir_recursive_absolute(SAVE_DIR)
+
+    var tmp_path := _tmp_path(profile_id)
+    var tmp_file := FileAccess.open(tmp_path, FileAccess.WRITE)
+    if tmp_file == null:
+        return false
+    tmp_file.store_string(JSON.stringify(data))
+    tmp_file.close()
+
+    var main_path := _save_path(profile_id)
+    if FileAccess.file_exists(main_path):
+        _copy_file(main_path, _backup_path(profile_id))
+
+    var dir := DirAccess.open(SAVE_DIR)
+    if dir == null:
+        return false
+    return dir.rename(tmp_path, main_path) == OK
+
+
+## Lit la sauvegarde d'un profil, deja migree vers le schema courant et
+## validee contre `schema`. Retourne null si le fichier principal est absent,
+## corrompu ou invalide ET que la copie de secours l'est aussi (ou n'existe
+## pas).
+static func read(profile_id: String, schema: Dictionary) -> Variant:
+    var from_main: Variant = _try_read(_save_path(profile_id), schema)
+    if from_main != null:
+        return from_main
+    return _try_read(_backup_path(profile_id), schema)
+
+
+static func delete(profile_id: String) -> void:
+    var dir := DirAccess.open(SAVE_DIR)
+    if dir == null:
+        return
+    for path in [_save_path(profile_id), _backup_path(profile_id), _tmp_path(profile_id)]:
+        if FileAccess.file_exists(path):
+            dir.remove(path.get_file())
+
+
+static func list_profile_ids() -> Array[String]:
+    var ids: Array[String] = []
+    var dir := DirAccess.open(SAVE_DIR)
+    if dir == null:
+        return ids
+    dir.list_dir_begin()
+    var entry := dir.get_next()
+    while entry != "":
+        if entry.ends_with(".json") and not entry.ends_with(".backup.json"):
+            ids.append(entry.get_basename())
+        entry = dir.get_next()
+    return ids
+
+
+static func _try_read(path: String, schema: Dictionary) -> Variant:
+    var parsed: Variant = _read_raw_json(path)
+    if typeof(parsed) != TYPE_DICTIONARY:
+        return null
+    var migrated: Dictionary = SaveMigration.migrate(parsed)
+    if migrated.is_empty():
+        return null
+    var errors: Array[String] = SchemaValidator.validate(migrated, schema)
+    if not errors.is_empty():
+        return null
+    return migrated
+
+
+static func _read_raw_json(path: String) -> Variant:
+    if not FileAccess.file_exists(path):
+        return null
+    var file := FileAccess.open(path, FileAccess.READ)
+    if file == null:
+        return null
+    var text := file.get_as_text()
+    if text.strip_edges().is_empty():
+        return null
+    return JSON.parse_string(text)
+
+
+static func _copy_file(from_path: String, to_path: String) -> void:
+    var source := FileAccess.open(from_path, FileAccess.READ)
+    if source == null:
+        return
+    var bytes := source.get_buffer(source.get_length())
+    source.close()
+    var dest := FileAccess.open(to_path, FileAccess.WRITE)
+    if dest == null:
+        return
+    dest.store_buffer(bytes)
+    dest.close()
+
+
+static func _save_path(profile_id: String) -> String:
+    return "%s/%s.json" % [SAVE_DIR, profile_id]
+
+
+static func _tmp_path(profile_id: String) -> String:
+    return "%s/%s.json.tmp" % [SAVE_DIR, profile_id]
+
+
+static func _backup_path(profile_id: String) -> String:
+    return "%s/%s.backup.json" % [SAVE_DIR, profile_id]

scripts/profiles/save_io.gd.uid

@@ -0,0 +1 @@
+uid://cnsull4s5riep

scripts/profiles/save_migration.gd

@@ -0,0 +1,30 @@
+class_name SaveMigration
+extends RefCounted
+## Migration des sauvegardes entre versions de schema. Code pur. Une seule
+## version existe pour l'instant (1) ; chaque montee de version future ajoute
+## une etape a la chaine ci-dessous, sans jamais reecrire les etapes passees.
+
+const CURRENT_SCHEMA_VERSION := 1
+
+
+## Retourne un dictionnaire vide si la version est absente, invalide, ou plus
+## recente que ce que cette version du moteur sait lire : refuser plutot que
+## de deviner et corrompre la progression de l'enfant.
+static func migrate(data: Dictionary) -> Dictionary:
+    if not data.has("schema_version"):
+        return {}
+    var version: Variant = data["schema_version"]
+    if typeof(version) != TYPE_INT and typeof(version) != TYPE_FLOAT:
+        return {}
+    var version_int: int = int(version)
+    if version_int < 1 or version_int > CURRENT_SCHEMA_VERSION:
+        return {}
+
+    var migrated: Dictionary = data.duplicate(true)
+    # Chaine de montees de version, a completer quand CURRENT_SCHEMA_VERSION
+    # augmentera :
+    # if version_int == 1:
+    #     migrated = _migrate_v1_to_v2(migrated)
+    #     version_int = 2
+    migrated["schema_version"] = CURRENT_SCHEMA_VERSION
+    return migrated

scripts/profiles/save_migration.gd.uid

@@ -0,0 +1 @@
+uid://ct1yblqd7jxtw