fix: sync typed-nil dependency validation

cmd/telesrv/main.go

@@ -854,7 +854,7 @@ func run(logger *zap.Logger) error {
 		EphemeralPush:        ephemeralStore,
 		EphemeralReports:     ephemeralReportStore,
 		Users:                usersService,
-		TelegramLogin:        telegramLoginService,
+		TelegramLogin:        telegramLoginRPCDependency(telegramLoginService),
 		Updates:              updatesService,
 		BootstrapUpdates:     bootstrapUpdateStore,
 		BotAPIUpdates:        botAPIUpdateStore,
@@ -1047,6 +1047,17 @@ func run(logger *zap.Logger) error {
 	return srv.ListenAndServe(ctx, cfg.ListenAddr)
 }
 
+// telegramLoginRPCDependency preserves a disabled Telegram Login service as a
+// nil interface. Assigning the nil *Service directly to rpc.Deps would create a
+// non-nil interface with a nil concrete pointer and bypass Router availability
+// checks.
+func telegramLoginRPCDependency(service *telegramloginapp.Service) rpc.TelegramLoginService {
+	if service == nil {
+		return nil
+	}
+	return service
+}
+
 func runTelegramLoginRetention(ctx context.Context, service *telegramloginapp.Service, retention, interval time.Duration, batch int, logger *zap.Logger) {
 	run := func() {
 		var total int64

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)
+	}
+}