Move network code into its own dusknetwork module, gate behind DUSK_NETWORK

Splits the platform-agnostic network core out of dusk into a top-level
dusknetwork module, mirroring the duskgl/dusksdl2 pattern. Adds a
DUSK_NETWORK cmake option (default ON) so builds can exclude all
networking code, including the per-platform implementations.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/dusknetwork/network/networkinfo.h

@@ -0,0 +1,51 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "dusk.h"
+
+#define NETWORK_INFO_IPV4_DNS_COUNT_MAX 2
+#define NETWORK_INFO_IPV4_OCTET_COUNT 4
+#define NETWORK_INFO_IPV6_OCTET_COUNT 16
+#define NETWORK_INFO_IPV6_DNS_COUNT_MAX 2
+#define NETWORK_INFO_FORMAT_IPV4 "%u.%u.%u.%u"
+#define NETWORK_INFO_FORMAT_IPV6 \
+  "%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x"
+
+typedef enum {
+  NETWORK_TYPE_IPV4,
+  #ifdef DUSK_NETWORK_IPV6
+    NETWORK_TYPE_IPV6,
+  #endif
+} networktype_t;
+
+typedef struct {
+  uint8_t ip[NETWORK_INFO_IPV4_OCTET_COUNT];
+} networkinfoipv4_t;
+
+#ifdef DUSK_NETWORK_IPV6
+  typedef struct {
+    uint8_t ip[NETWORK_INFO_IPV6_OCTET_COUNT];
+  } networkinfoipv6_t;
+#endif
+
+typedef struct {
+  networktype_t type;
+  union {
+    networkinfoipv4_t ipv4;
+    #ifdef DUSK_NETWORK_IPV6
+      networkinfoipv6_t ipv6;
+    #endif
+  };
+} networkinfo_t;
+
+/**
+ * Returns the network information for the currently active network connection.
+ * 
+ * @return Network information for the currently active network connection.
+ */
+networkinfo_t networkGetInfo();