Implement production vertical slice foundation

game/domain/dive/oxygen_snapshot.gd

@@ -0,0 +1,22 @@
+class_name OxygenSnapshot
+extends RefCounted
+
+var remaining_l: float
+var maximum_l: float
+var ratio: float
+var consumption_l_per_min: float
+var endurance_minutes: float
+
+
+func _init(
+	p_remaining_l: float,
+	p_maximum_l: float,
+	p_consumption_l_per_min: float
+) -> void:
+	remaining_l = p_remaining_l
+	maximum_l = p_maximum_l
+	ratio = remaining_l / maximum_l if maximum_l > 0.0 else 0.0
+	consumption_l_per_min = p_consumption_l_per_min
+	endurance_minutes = (
+		remaining_l / consumption_l_per_min if consumption_l_per_min > 0.0 else INF
+	)