Visual overhaul: theme, illustrations, redesigned screens (0.3.0)

Phase "habillage" of the post-0.1.0 plan. Rendering was reviewed on real
screenshots (new tools/screenshot.gd, `make screenshot`), which also
caught and fixed map markers overlapping and truncated titles.

- Global Godot theme (Atkinson Hyperlegible font, cream/green/gold
  palette, raised buttons, rounded cards, thick keyboard focus).
- Original vector art: forest/marsh backdrops, Plume the owl, stars,
  exercise-type icons, correct/try-again icons, 10 collection items.
- Redesigned world map (markers as cards with icon, title and stars,
  responsive layout), profile screens, mission intro, exercise host,
  rule/feedback panels, reward screen and collection grid.
- Motion helper (pop-in, fade) honouring an animations setting.
- Settings: animations flag; base window 1152x648 with canvas_items.

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

scenes/ui/reward_screen.gd

@@ -5,23 +5,37 @@ extends Control
 ## au moins une etoile. Sauvegarde groupee ici, en fin de mission
 ## (docs/specs/decisions.md point 7).
 
+const STAR_FULL := preload("res://assets/interface/star_full.svg")
+const STAR_EMPTY := preload("res://assets/interface/star_empty.svg")
+const STAR_SIZE := 88.0
+const ITEM_SIZE := 72.0
+
+@onready var _backdrop: Control = %Backdrop
 @onready var _title_label: Label = %TitleLabel
+@onready var _stars_row: HBoxContainer = %StarsRow
 @onready var _stars_label: Label = %StarsLabel
 @onready var _message_label: Label = %MessageLabel
 @onready var _record_label: Label = %RecordLabel
 @onready var _total_label: Label = %TotalLabel
+@onready var _new_items_box: VBoxContainer = %NewItemsBox
 @onready var _new_items_label: Label = %NewItemsLabel
+@onready var _new_items_row: HBoxContainer = %NewItemsRow
 @onready var _collection_button: Button = %CollectionButton
 @onready var _continue_button: Button = %ContinueButton
 
 
 func _ready() -> void:
+    var mission := ExerciseEngine.get_mission(GameManager.pending_mission_id)
+    var rule := ExerciseEngine.get_rule(mission.get("rule_id", ""))
+    _backdrop.kind = "marsh" if rule.get("level", "CE1") == "CE2" else "forest"
+
     var summary := ProgressManager.complete_mission(
         GameManager.pending_mission_id, GameManager.last_outcomes
     )
     ProgressManager.save_now()
 
     _title_label.text = UIText.get_text("reward_screen.title")
+    _show_stars(summary["stars"])
     _stars_label.text = (
         "%s %d/%d"
         % [UIText.get_text("reward_screen.stars_label"), summary["stars"], MissionScoring.MAX_STARS]
@@ -32,17 +46,7 @@ func _ready() -> void:
     _total_label.text = (
         "%s %d" % [UIText.get_text("reward_screen.total_label"), summary["total_stars"]]
     )
-
-    var new_items: Array = summary["new_items"]
-    _new_items_label.visible = not new_items.is_empty()
-    if not new_items.is_empty():
-        var titles: Array[String] = []
-        for item in ExerciseEngine.get_reward_items():
-            if new_items.has(item["item_id"]):
-                titles.append(item["title"])
-        _new_items_label.text = (
-            "%s\n%s" % [UIText.get_text("reward_screen.new_items_label"), "\n".join(titles)]
-        )
+    _show_new_items(summary["new_items"])
 
     _collection_button.text = UIText.get_text("reward_screen.collection_button")
     _collection_button.pressed.connect(_on_collection_pressed)
@@ -50,6 +54,45 @@ func _ready() -> void:
     _continue_button.pressed.connect(_on_continue_pressed)
 
 
+func _show_stars(earned: int) -> void:
+    for i in MissionScoring.MAX_STARS:
+        var star := TextureRect.new()
+        star.texture = STAR_FULL if i < earned else STAR_EMPTY
+        star.custom_minimum_size = Vector2(STAR_SIZE, STAR_SIZE)
+        star.expand_mode = TextureRect.EXPAND_IGNORE_SIZE
+        star.stretch_mode = TextureRect.STRETCH_KEEP_ASPECT_CENTERED
+        _stars_row.add_child(star)
+        if i < earned:
+            Motion.pop_in(star, 0.25 + 0.2 * i)
+
+
+func _show_new_items(new_items: Array) -> void:
+    _new_items_box.visible = not new_items.is_empty()
+    if new_items.is_empty():
+        return
+    _new_items_label.text = UIText.get_text("reward_screen.new_items_label")
+    var index := 0
+    for item in ExerciseEngine.get_reward_items():
+        if not new_items.has(item["item_id"]):
+            continue
+        var holder := VBoxContainer.new()
+        var icon := TextureRect.new()
+        icon.texture = ItemIcons.texture_for(item["item_id"])
+        icon.custom_minimum_size = Vector2(ITEM_SIZE, ITEM_SIZE)
+        icon.expand_mode = TextureRect.EXPAND_IGNORE_SIZE
+        icon.stretch_mode = TextureRect.STRETCH_KEEP_ASPECT_CENTERED
+        icon.size_flags_horizontal = Control.SIZE_SHRINK_CENTER
+        holder.add_child(icon)
+        var name_label := Label.new()
+        name_label.text = item["title"]
+        name_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
+        name_label.theme_type_variation = &"Small"
+        holder.add_child(name_label)
+        _new_items_row.add_child(holder)
+        Motion.pop_in(holder, 0.8 + 0.15 * index)
+        index += 1
+
+
 func _on_collection_pressed() -> void:
     GameManager.pending_mission_id = ""
     GameManager.goto(GameManager.SCENE_COLLECTION)