refactor: чистка мёртвого кода, лимит ходов D3, HTML-экранирование и UTF-8 обрезка в Telegram

internal/chat/telegram/telegram_test.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 	"testing"
 	"time"
+	"unicode/utf8"
 
 	"github.com/kamelion/ratatoskr-go/internal/chat"
 )
@@ -111,6 +112,36 @@ func TestSendWithOptions(t *testing.T) {
 	}
 }
 
+func TestFormatOutgoingEscapesText(t *testing.T) {
+	if got := formatOutgoing(chat.Message{Text: "2 < 3 & 4 > 1"}); got != "2 &lt; 3 &amp; 4 &gt; 1" {
+		t.Errorf("text escape = %q", got)
+	}
+	got := formatOutgoing(chat.Message{
+		Text:    "a<b",
+		Options: []chat.Option{{ID: "x", Label: "l&l"}},
+	})
+	if !strings.Contains(got, "a&lt;b") || !strings.Contains(got, "l&amp;l") {
+		t.Errorf("options escape = %q", got)
+	}
+}
+
+func TestTruncateUTF8(t *testing.T) {
+	long := strings.Repeat("я", 5000)
+	tr := truncateUTF8(long, 4000)
+	if len(tr) != 4000 {
+		t.Fatalf("len = %d, want 4000", len(tr))
+	}
+	if !utf8.ValidString(tr) {
+		t.Fatal("truncated string is not valid UTF-8")
+	}
+	if got := truncateUTF8("привет", 4000); got != "привет" {
+		t.Fatalf("short text changed: %q", got)
+	}
+	if got := truncateUTF8("", 4000); got != "" {
+		t.Fatalf("empty text changed: %q", got)
+	}
+}
+
 func TestIncoming(t *testing.T) {
 	f := newFakeTG(t)
 	ch := New("TOKEN", time.Second)
@@ -143,4 +174,4 @@ func TestIncoming(t *testing.T) {
 	case <-ctx.Done():
 		t.Fatal("timeout ожидания входящего")
 	}
-}
+}