Refactor Reticulum runtime and delivery state

Split LXMF runtime ownership into focused peer, path, link, propagation, and delivery helpers while keeping the adapter as the coordination layer.

Make chat delivery refs and send-result events protocol-aware across Reticulum, Meshtastic, and MeshCore, including Sent/Delivered/Failed semantics, UI badges, retry lookup, and store persistence.

Fix Meshtastic MQTT private replies to publish encrypted direct packets and cover the new delivery behavior with smoke tests.

modules/chat_presentation_adapters/src/chat_message_mapper.cpp

@@ -63,6 +63,7 @@ ui::chat::MessageRef toUiMessageRef(const chat::ChatMessage& message)
     }
 
     out.protocol_id = message.msg_id;
+    out.protocol = static_cast<uint8_t>(message.protocol);
     return out;
 }