feat(progression): combo de mining + multiplicateur XP

Nouvel autoload ComboTracker: chaque cassage de bloc dans les 1.8s du
précédent étend le combo (+15% par palier, cap x3.0). Le multiplicateur
s'applique au gain XP de base.

HUD: panneau "COMBO xN (+X%)" animé (pop scale) à partir de x2, avec
barre de temps restant qui se vide. Combo ≥5 au break → bonus XP final
(3 * count) avec popup.

Rétention: incite à chaîner les actions, récompense la dextérité et crée
des pics d'intensité dans la boucle.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/Main.gd

@@ -247,7 +247,12 @@ func _award_break_xp(block_id: int, hit_position: Vector3) -> void:
 	var pp: Node = get_node_or_null("/root/PlayerProgress")
 	if pp == null:
 		return
-	var gain: int = pp.XP_BREAK_BY_BLOCK.get(block_id, pp.XP_BREAK_DEFAULT)
+	var base_gain: int = pp.XP_BREAK_BY_BLOCK.get(block_id, pp.XP_BREAK_DEFAULT)
+	var combo: Node = get_node_or_null("/root/ComboTracker")
+	var mult: float = 1.0
+	if combo != null:
+		mult = combo.bump()
+	var gain: int = int(round(base_gain * mult))
 	pp.award(gain, "bloc", hit_position)
 	_spawn_xp_popup(gain, hit_position)
 	var qm: Node = get_node_or_null("/root/QuestManager")

scripts/dolphin/HUD.gd

@@ -53,9 +53,14 @@ func _ready() -> void:
 		_on_quests_updated()
 	_build_toast_container()
 	_build_consumable_hint()
+	_build_combo_panel()
 	var am: Node = get_node_or_null("/root/AchievementManager")
 	if am != null:
 		am.achievement_unlocked.connect(_on_achievement_unlocked)
+	var combo: Node = get_node_or_null("/root/ComboTracker")
+	if combo != null:
+		combo.combo_changed.connect(_on_combo_changed)
+		combo.combo_broken.connect(_on_combo_broken)
 
 
 func _build_info_panel() -> void:
@@ -242,6 +247,91 @@ func _on_quest_completed(q: Dictionary) -> void:
 
 var _consumable_hint: Label = null
 
+var _combo_panel: PanelContainer = null
+var _combo_label: Label = null
+var _combo_bar: ProgressBar = null
+
+
+func _build_combo_panel() -> void:
+	_combo_panel = PanelContainer.new()
+	_combo_panel.anchor_left = 0.5
+	_combo_panel.anchor_right = 0.5
+	_combo_panel.anchor_top = 0.5
+	_combo_panel.anchor_bottom = 0.5
+	_combo_panel.offset_left = 120.0
+	_combo_panel.offset_right = 320.0
+	_combo_panel.offset_top = 30.0
+	_combo_panel.offset_bottom = 80.0
+
+	var style := StyleBoxFlat.new()
+	style.bg_color = Color(0.2, 0.08, 0.05, 0.85)
+	style.border_color = Color(1.0, 0.55, 0.15)
+	style.set_border_width_all(2)
+	style.set_corner_radius_all(8)
+	_combo_panel.add_theme_stylebox_override("panel", style)
+
+	var vbox := VBoxContainer.new()
+	vbox.add_theme_constant_override("separation", 2)
+	_combo_panel.add_child(vbox)
+
+	_combo_label = Label.new()
+	_combo_label.text = "COMBO x1"
+	_combo_label.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
+	_combo_label.add_theme_font_size_override("font_size", 20)
+	_combo_label.add_theme_color_override("font_color", Color(1.0, 0.85, 0.3))
+	_combo_label.add_theme_color_override("font_outline_color", Color(0, 0, 0, 0.9))
+	_combo_label.add_theme_constant_override("outline_size", 4)
+	vbox.add_child(_combo_label)
+
+	_combo_bar = ProgressBar.new()
+	_combo_bar.max_value = 1.0
+	_combo_bar.value = 0.0
+	_combo_bar.custom_minimum_size = Vector2(180, 4)
+	_combo_bar.show_percentage = false
+	var fill := StyleBoxFlat.new()
+	fill.bg_color = Color(1.0, 0.55, 0.15)
+	fill.set_corner_radius_all(2)
+	_combo_bar.add_theme_stylebox_override("fill", fill)
+	var bg := StyleBoxFlat.new()
+	bg.bg_color = Color(0.1, 0.05, 0.03, 0.8)
+	bg.set_corner_radius_all(2)
+	_combo_bar.add_theme_stylebox_override("background", bg)
+	vbox.add_child(_combo_bar)
+
+	_combo_panel.visible = false
+	add_child(_combo_panel)
+
+
+func _on_combo_changed(cnt: int, mult: float) -> void:
+	if _combo_panel == null:
+		return
+	if cnt < 2:
+		_combo_panel.visible = false
+		return
+	_combo_panel.visible = true
+	_combo_label.text = "COMBO x%d  (+%d%%)" % [cnt, int(round((mult - 1.0) * 100.0))]
+	_combo_panel.scale = Vector2(1.15, 1.15)
+	var tween := create_tween()
+	tween.tween_property(_combo_panel, "scale", Vector2.ONE, 0.18).set_trans(Tween.TRANS_SINE)
+
+
+func _on_combo_broken(final_count: int) -> void:
+	if final_count >= 5:
+		var pp: Node = get_node_or_null("/root/PlayerProgress")
+		if pp != null:
+			var bonus: int = final_count * 3
+			pp.award(bonus, "bonus combo x%d" % final_count, Vector3.ZERO)
+			var main: Node = get_tree().get_first_node_in_group("main")
+			if main != null and is_instance_valid(_dolphin) and main.has_method("_spawn_xp_popup"):
+				main.call("_spawn_xp_popup", bonus, _dolphin.global_position + Vector3(0, 2.0, 0))
+
+
+func _update_combo_bar() -> void:
+	var combo: Node = get_node_or_null("/root/ComboTracker")
+	if combo == null or _combo_bar == null:
+		return
+	_combo_bar.value = combo.time_remaining_ratio()
+
 
 func _build_consumable_hint() -> void:
 	_consumable_hint = Label.new()
@@ -455,6 +545,7 @@ func _process(delta: float) -> void:
 
 	_update_toasts(delta)
 	_update_consumable_hint()
+	_update_combo_bar()
 
 	if not is_instance_valid(_dolphin):
 		return

scripts/progression/ComboTracker.gd

@@ -0,0 +1,48 @@
+extends Node
+
+signal combo_changed(count: int, multiplier: float)
+signal combo_broken(final_count: int)
+
+const WINDOW_SEC: float = 1.8
+const STEP_BONUS: float = 0.15  # +15% per combo step
+const MAX_MULT: float = 3.0
+
+var count: int = 0
+var multiplier: float = 1.0
+var _timer: float = 0.0
+var _active: bool = false
+
+
+func _process(delta: float) -> void:
+	if not _active:
+		return
+	_timer -= delta
+	if _timer <= 0.0:
+		_break()
+
+
+func bump() -> float:
+	# Advances combo and returns multiplier to apply to the triggering gain.
+	count += 1
+	multiplier = minf(1.0 + float(count - 1) * STEP_BONUS, MAX_MULT)
+	_timer = WINDOW_SEC
+	_active = true
+	combo_changed.emit(count, multiplier)
+	return multiplier
+
+
+func _break() -> void:
+	var final_count: int = count
+	_active = false
+	combo_changed.emit(0, 1.0)
+	if final_count >= 2:
+		combo_broken.emit(final_count)
+	count = 0
+	multiplier = 1.0
+	_timer = 0.0
+
+
+func time_remaining_ratio() -> float:
+	if not _active:
+		return 0.0
+	return clampf(_timer / WINDOW_SEC, 0.0, 1.0)