Summary

Update udp_facade to return i_protocol_client and i_protocol_server instead of protocol-specific i_udp_client and i_udp_server interfaces.

Part of #577

Problem

Currently, udp_facade returns protocol-specific interfaces:

• create_client() returns std::shared_ptr<interfaces::i_udp_client>
• create_server() returns std::shared_ptr<interfaces::i_udp_server>

This prevents moving protocol-specific interfaces to internal, blocking the EPIC goal of reducing public header count.

Solution

Follow the pattern established in tcp_facade.h:

1. Update udp_facade.h includes:

   • Remove: #include "kcenon/network/interfaces/i_udp_client.h"
   • Remove: #include "kcenon/network/interfaces/i_udp_server.h"
   • Add: #include "kcenon/network/interfaces/i_protocol_client.h"
   • Add: #include "kcenon/network/interfaces/i_protocol_server.h"

2. Update return types:

   • create_client() → std::shared_ptr<interfaces::i_protocol_client>
   • create_server() → std::shared_ptr<interfaces::i_protocol_server>

3. Update udp_facade.cpp implementation:

   • Ensure messaging_udp_client implements i_protocol_client
   • Ensure messaging_udp_server implements i_protocol_server

4. Update documentation to reflect new return types

Acceptance Criteria

• udp_facade.h includes i_protocol_client.h and i_protocol_server.h
• create_client() returns i_protocol_client pointer
• create_server() returns i_protocol_server pointer
• All existing tests pass
• No breaking changes to existing code (polymorphism preserved)
• Documentation updated

References

• Pattern reference: tcp_facade.h (lines 180-201)
• Related issue: refactor: Create common protocol interfaces (IProtocolClient, IProtocolServer) #593 (common protocol interfaces)