feat(武器系统): 完善武器获取和提炼逻辑

- 在WeaponShow.gd中修改操作标签文本为"获得武器"和"提炼灵魂"
- 在Feed.gd中添加武器获取逻辑，区分已有武器和新增武器情况
- 在EntityBase.gd中重构武器图标更新逻辑，提取为rebuildWeaponIcons方法

scripts/Structs/Feed.gd

@@ -51,6 +51,18 @@ func apply(entity: EntityBase):
 			if !applier or applier.call(entity, value):
 				entity.fields[field] += value
 				entity.fields[field] = clamp(entity.fields[field], 0, FieldStore.entityMaxValueMap.get(field, INF))
+		for i in weapons:
+			var instance = i.instantiate() as Weapon
+			if UIState.player.weaponBag.has(instance.displayName):
+				UIState.player.getItem({
+					ItemStore.ItemType.SOUL: instance.soulLevel
+				})
+			else:
+				instance.hide()
+				entity.weapons.append(instance)
+				entity.weaponBag.append(instance.displayName)
+				entity.weaponStore.add_child(instance)
+				entity.rebuildWeaponIcons()
 		hide()
 	selected.emit(allHave)
 	return allHave