Refine movement, water recovery, and UI baseline

world/player_water_trigger.gd

@@ -0,0 +1,46 @@
+class_name PlayerWaterTrigger
+extends Area3D
+
+signal recovery_requested(player: Player, surface_height: float)
+
+@export var surface_height: float = 0.2
+@export_range(0.0, 2.0, 0.05) var entry_depth_threshold: float = 0.35
+
+var _tracked_players: Array[Player] = []
+var _triggered_players: Dictionary[StringName, bool] = {}
+
+
+func _ready() -> void:
+	body_entered.connect(_on_body_entered)
+	body_exited.connect(_on_body_exited)
+
+
+func _physics_process(_delta: float) -> void:
+	for player: Player in _tracked_players.duplicate():
+		if not is_instance_valid(player):
+			_tracked_players.erase(player)
+			continue
+		var player_key: StringName = StringName(str(player.get_instance_id()))
+		if _triggered_players.has(player_key):
+			continue
+		if (
+			player.get_body_center_position().y
+			<= surface_height - entry_depth_threshold
+		):
+			_triggered_players[player_key] = true
+			recovery_requested.emit(player, surface_height)
+
+
+func _on_body_entered(body: Node3D) -> void:
+	var player: Player = body as Player
+	if player == null or player in _tracked_players:
+		return
+	_tracked_players.append(player)
+
+
+func _on_body_exited(body: Node3D) -> void:
+	var player: Player = body as Player
+	if player == null:
+		return
+	_tracked_players.erase(player)
+	_triggered_players.erase(StringName(str(player.get_instance_id())))