fix: avoid C-style array in default announce address for Clang-Tidy

Use an inline accessor returning the multicast string literal instead of a
constexpr char array.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: TrentHouliston

src/nuclearnet/NUClearNet.hpp

@@ -53,7 +53,7 @@ namespace network {
         /// This node's name on the network
         std::string name;
         /// The multicast/broadcast/unicast address to announce on
-        std::string announce_address = DEFAULT_ANNOUNCE_ADDRESS;
+        std::string announce_address = default_announce_address();
         /// The port to use for announce discovery
         in_port_t announce_port = 7447;
         /// Address to bind to (empty = all interfaces)

src/nuclearnet/wire_protocol.hpp

@@ -42,7 +42,9 @@ namespace network {
     constexpr uint8_t PROTOCOL_VERSION = 0x03;
 
     /// Default organization-local multicast address for peer discovery (RFC 2365)
-    constexpr const char DEFAULT_ANNOUNCE_ADDRESS[] = "239.226.152.162";  // NOSONAR
+    inline const char* default_announce_address() {
+        return "239.226.152.162";  // NOSONAR
+    }
 
     /// Packet type identifiers
     enum PacketType : uint8_t {