fix: sync typed-nil dependency validation

cmd/telesrv/main_test.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"testing"
+
+	telegramloginapp "telesrv/internal/app/telegramlogin"
+)
+
+func TestTelegramLoginRPCDependencyPreservesDisabledNil(t *testing.T) {
+	var disabled *telegramloginapp.Service
+	if dependency := telegramLoginRPCDependency(disabled); dependency != nil {
+		t.Fatalf("disabled Telegram Login dependency = %#v, want nil interface", dependency)
+	}
+}
+
+func TestTelegramLoginRPCDependencyPreservesEnabledService(t *testing.T) {
+	enabled := new(telegramloginapp.Service)
+	if dependency := telegramLoginRPCDependency(enabled); dependency != enabled {
+		t.Fatalf("enabled Telegram Login dependency = %#v, want %p", dependency, enabled)
+	}
+}