feat: add networking module with TCP Socket/Server and example applications

Implement a full-featured `net` module supporting TCP `Socket` and `Server` classes via libuv, including example applications (chat server, echo server, HTTP client/server, file explorer, system dashboard) and benchmark scripts (fibonacci, n-body). Add GEMINI.md project documentation and Stderr class to io module.

example/http_client.wren

@@ -0,0 +1,42 @@
+// retoor <retoor@molodetz.nl>
+import "net" for Socket
+import "scheduler" for Scheduler
+
+class HttpClient {
+  static get(host, port, path) {
+    System.print("Connecting to %(host):%(port)...")
+    var socket = Socket.connect(host, port)
+    
+    var request = "GET %(path) HTTP/1.1\r\n" + 
+                  "Host: %(host)\r\n" + 
+                  "User-Agent: Wren-CLI\r\n" + 
+                  "Connection: close\r\n" + 
+                  "\r\n"
+    
+    System.print("Sending request...")
+    socket.write(request)
+    
+    System.print("Waiting for response...")
+    var response = ""
+    while (true) {
+      var chunk = socket.read()
+      if (chunk == null) break
+      response = response + chunk
+    }
+    
+    socket.close()
+    return response
+  }
+}
+
+// Example usage: Fetching from a local server or a known public IP
+// Note: This implementation is for raw IP/DNS if supported by uv_tcp_connect.
+// Since our net.c uses uv_ip4_addr, we use localhost for the example.
+var host = "127.0.0.1"
+var port = 8080 // Try to connect to our own http_server example
+var path = "/"
+
+var result = HttpClient.get(host, port, path)
+System.print("\n--- Response Received ---
+")
+System.print(result)