修复 Create Simulated 绳索连接器崩溃
Fix for Create Simulated Rope Connector Crash
问题 / The Problem
在服务器中游玩时，当准星对准物理化结构上连接了绳索的绳索连接器（Rope Connector）时，游戏会立即崩溃。
When playing on a multiplayer server, the game crashes immediately when the player's crosshair is aimed at a Rope Connector that is part of a physicalized structure and has ropes connected to it.
原因 / The Cause
Create: Aeronautics 1.3.0 的 RopeStrandHolderBehavior.addServerStrand() 方法在客户端也会执行，但内部调用了服务端专属的 ServerLevelRopeManager，导致空指针异常。
The RopeStrandHolderBehavior.addServerStrand() method in Create: Aeronautics 1.3.0 is executed on the client side as well, but it internally calls the server-exclusive ServerLevelRopeManager, resulting in a NullPointerException (NPE).
修复 / The Fix
通过 Mixin 在方法开头添加客户端检查，阻止在客户端执行服务端逻辑。
This mod uses a Mixin to inject a client-side check at the beginning of the method, preventing the execution of server-side logic on the client.
兼容性
- Minecraft: 1.21.1
- NeoForge: 21.1.236+
- Create Simulated: 1.3.0
说明 / Note
这是一个临时修复补丁。一旦 Create Simulated 官方发布修复版本，本模组将不再需要。
This is a temporary hotfix patch. Once the official Create Simulated mod releases an update containing this fix, this mod will no longer be needed.