Motivation

• Provide a way for Unity clients to send RPCs to one or more specific clients while preserving existing broadcast behavior.
• Maintain compatibility with the current server protocol without adding new server-side message types.
• Keep RPC filtering logic client-side so that non-targeted clients ignore targeted RPCs.

Description

• Add overloaded APIs RpcTo(int targetClientNo, string functionName, string[] args = null) and RpcTo(int[] targetClientNos, string functionName, string[] args = null) to NetSyncManager for single and multi-target sends.
• Introduce TargetedRpcPayload and SystemRpcToFunctionName = "rpc_to" and serialize the payload with JsonConvert.SerializeObject to send as an internal system RPC via Rpc_SystemRPC.
• Extend the system RPC handler to handle rpc_to by deserializing the payload in HandleTargetedRpc, checking if the local _clientNo is included in targetClientNos, and invoking OnRPCReceived only for matching targets.
• Changes are localized to STYLY-NetSync-Unity/Packages/com.styly.styly-netsync/Runtime/NetSyncManager.cs and do not alter the broadcast Rpc(...) behavior.

Testing

• Ran git diff --check to validate whitespace and patch issues and it completed without errors.
• Searched for the new symbols with rg -n "public void RpcTo|HandleTargetedRpc|SystemRpcToFunctionName" to verify the additions and the search returned the expected locations.
• Performed quick file inspection of NetSyncManager.cs to confirm insertion points and handler wiring succeeded and found no compile-time formatting issues.

Codex Task