fix: address staticcheck lint issues

- avoid deprecated DefaultIdleTimeout, use time.Minute directly
- simplify embedded field selectors (QF1008)

mtglib/conns.go

@@ -104,13 +104,13 @@ type connIdleTimeout struct {
 }
 
 func (c connIdleTimeout) Read(b []byte) (int, error) {
-	c.Conn.SetReadDeadline(time.Now().Add(c.timeout)) //nolint: errcheck
+	c.SetReadDeadline(time.Now().Add(c.timeout)) //nolint: errcheck
 
 	return c.Conn.Read(b) //nolint: wrapcheck
 }
 
 func (c connIdleTimeout) Write(b []byte) (int, error) {
-	c.Conn.SetWriteDeadline(time.Now().Add(c.timeout)) //nolint: errcheck
+	c.SetWriteDeadline(time.Now().Add(c.timeout)) //nolint: errcheck
 
 	return c.Conn.Write(b) //nolint: wrapcheck
 }

mtglib/proxy_opts.go

@@ -218,7 +218,7 @@ func (p ProxyOpts) getPreferIP() string {
 
 func (p ProxyOpts) getIdleTimeout() time.Duration {
 	if p.IdleTimeout == 0 {
-		return DefaultIdleTimeout
+		return time.Minute
 	}
 
 	return p.IdleTimeout