Add choice between five background music tracks (0.5.1)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

scripts/audio/sound_catalog.gd

@@ -7,7 +7,10 @@ const SFX_DIR := "res://assets/audio/sfx"
 const MUSIC_DIR := "res://assets/audio/music"
 
 const SFX_IDS: Array[String] = ["click", "success", "try_again", "star", "fanfare"]
-const MUSIC_IDS: Array[String] = ["forest", "marsh"]
+const MUSIC_IDS: Array[String] = ["forest", "marsh", "meadow", "river", "night"]
+
+## Choix « automatique » : la musique de la region (voir music_for_level).
+const MUSIC_AUTO := "auto"
 
 
 static func sfx_path(sfx_id: String) -> String:
@@ -25,3 +28,17 @@ static func music_path(music_id: String) -> String:
 ## Musique d'une region selon le niveau scolaire de la regle.
 static func music_for_level(level: String) -> String:
     return "marsh" if level == "CE2" else "forest"
+
+
+## Choix possibles dans les reglages : automatique puis chaque morceau.
+static func music_choices() -> Array[String]:
+    var choices: Array[String] = [MUSIC_AUTO]
+    choices.append_array(MUSIC_IDS)
+    return choices
+
+
+## Morceau a jouer pour le choix de l'utilisateur et le niveau scolaire.
+static func resolve_music(choice: String, level: String) -> String:
+    if MUSIC_IDS.has(choice):
+        return choice
+    return music_for_level(level)

scripts/settings/app_settings.gd

@@ -22,6 +22,7 @@ static func defaults() -> Dictionary:
         "volume": 0.8,
         "music_volume": 0.5,
         "effects_volume": 0.8,
+        "music_track": SoundCatalog.MUSIC_AUTO,
         "text_scale_index": 0,
         "animations_enabled": true,
     }
@@ -41,6 +42,9 @@ static func sanitize(raw: Variant) -> Dictionary:
         var other: Variant = source.get(key)
         if typeof(other) == TYPE_FLOAT or typeof(other) == TYPE_INT:
             result[key] = clampf(float(other), 0.0, 1.0)
+    var track: Variant = source.get("music_track")
+    if typeof(track) == TYPE_STRING and SoundCatalog.music_choices().has(track):
+        result["music_track"] = track
     var index: Variant = source.get("text_scale_index")
     if typeof(index) == TYPE_FLOAT or typeof(index) == TYPE_INT:
         result["text_scale_index"] = clampi(int(index), 0, TEXT_SCALES.size() - 1)