fix(Weapons/Oxygener): 调整武器属性计算参数

将攻击力加成从0.5倍提升至1倍，火焰攻击力加成从0.25倍提升至0.5倍，并修正最大数量计算方式为加法而非乘法

scripts/Contents/Weapons/Oxygener.gd

@@ -2,9 +2,9 @@
 extends Weapon
 
 func update(to: int, origin: Dictionary, _entity: EntityBase):
-    origin["atk"] += 0.5 * to * soulLevel
-    origin["fireatk"] += 0.25 * to * soulLevel
-    origin["max-n"] *= soulLevel
+    origin["atk"] += 1 * to * soulLevel
+    origin["fireatk"] += 0.5 * to * soulLevel
+    origin["max-n"] += 2 * soulLevel
     return origin
 func attack(entity: EntityBase):
     var bulletName = MathTool.randomChoiceFromWeights(["OxygenFire", "AcidN"], [10, 1])