Initial Navis client with NaiveProxy, profiles, ping and git updates

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

internal/netcheck/ping.go

@@ -0,0 +1,69 @@
+package netcheck
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/url"
+	"strings"
+	"time"
+
+	"vpnclient/internal/protocols/naive"
+)
+
+// Result is a TCP reachability measurement to a proxy host.
+type Result struct {
+	Name    string `json:"name"`
+	Host    string `json:"host"`
+	Port    string `json:"port"`
+	Ms      int64  `json:"ms"`
+	OK      bool   `json:"ok"`
+	Error   string `json:"error,omitempty"`
+}
+
+// PingProxyURI measures TCP connect time to the host in a naive share/proxy URI.
+func PingProxyURI(ctx context.Context, name, proxyURI string) Result {
+	res := Result{Name: name}
+	if strings.TrimSpace(proxyURI) == "" {
+		res.Error = "нет ссылки сервера"
+		return res
+	}
+	normalized, err := naive.NormalizeProxyURI(proxyURI)
+	if err != nil {
+		res.Error = err.Error()
+		return res
+	}
+	u, err := url.Parse(normalized)
+	if err != nil {
+		res.Error = err.Error()
+		return res
+	}
+	host := u.Hostname()
+	port := u.Port()
+	if port == "" {
+		switch strings.ToLower(u.Scheme) {
+		case "https", "quic":
+			port = "443"
+		default:
+			port = "80"
+		}
+	}
+	res.Host = host
+	res.Port = port
+	if host == "" {
+		res.Error = "нет хоста"
+		return res
+	}
+
+	d := net.Dialer{Timeout: 4 * time.Second}
+	start := time.Now()
+	conn, err := d.DialContext(ctx, "tcp", net.JoinHostPort(host, port))
+	if err != nil {
+		res.Error = fmt.Sprintf("недоступен: %v", err)
+		return res
+	}
+	_ = conn.Close()
+	res.Ms = time.Since(start).Milliseconds()
+	res.OK = true
+	return res
+}