Refactor: Chia nho file main thao thu muc va don dep theo yeu cau

utils/network.py

@@ -0,0 +1,27 @@
+import socket
+
+def _resolve_hostname(ip):
+    """Reverse DNS lookup for a single IP."""
+    try:
+        return socket.gethostbyaddr(ip)[0]
+    except Exception:
+        return ""
+
+def get_local_ip():
+    """Get the local IP address of this machine."""
+    try:
+        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        s.connect(("8.8.8.8", 80))
+        ip = s.getsockname()[0]
+        s.close()
+        return ip
+    except Exception:
+        return "N/A"
+
+def get_default_network(ip):
+    """Guess the /24 network from local IP."""
+    try:
+        parts = ip.split(".")
+        return f"{parts[0]}.{parts[1]}.{parts[2]}.0/24"
+    except Exception:
+        return "192.168.1.0/24"