Motivation

• Provide an API to send RPCs from the Unity client to a specific client or a set of clients without changing existing broadcast behavior.

Description

• Added RpcTo(int targetClientNo, string functionName, string[] args = null) and RpcTo(int[] targetClientNos, string functionName, string[] args = null) to NetSyncManager to expose single/multi-client directed RPC sends while leaving Rpc(...) unchanged.
• Implemented RPCManager.SendTo(...) and helper methods to encode a target envelope into the function name using the internal format @target[2,3]|FunctionName and to sanitize targets (positive, unique client numbers).
• Added RPCManager.TryExtractTargetedFunction(...) to decode the envelope and return the decoded function name plus the target client set.
• Updated NetSyncManager.OnRPCReceivedHandler to use the decoder and drop incoming RPCs that include a target envelope but do not list the local ClientNo, so only intended recipients process the RPC.

Testing

• No automated tests were executed for the Unity runtime code in this headless environment.

Codex Task