fix: fail app on empty app url before parsing

frontend/src/lib/i18n/locales/it-IT.json

@@ -58,8 +58,8 @@
     "invalidInput": "Input non valido",
     "domainWarningTitle": "Dominio non valido",
     "domainWarningSubtitle": "Stai accedendo a questa istanza da un dominio errato. Scegliendo di procedere, potresti incontrare problemi con l'autenticazione.",
-    "domainWarningCurrent": "Attuale:",
-    "domainWarningExpected": "Previsto:",
+    "domainWarningCurrent": "Current:",
+    "domainWarningExpected": "Expected:",
     "ignoreTitle": "Ignora",
     "goToCorrectDomainTitle": "Vai al dominio corretto",
     "authorizeTitle": "Autorizza",

frontend/src/lib/i18n/locales/sr-SP.json

@@ -57,7 +57,7 @@
     "fieldRequired": "Ово поље је неопходно",
     "invalidInput": "Неисправан унос",
     "domainWarningTitle": "Неисправан домен",
-    "domainWarningSubtitle": "Приступате овој инстанци са неисправног домена. Ако наставите, можете наићи на проблеме са аутентификацијом.",
+    "domainWarningSubtitle": "You are accessing this instance from an incorrect domain. If you proceed, you may encounter issues with authentication.",
     "domainWarningCurrent": "Тренутни:",
     "domainWarningExpected": "Очекивани:",
     "ignoreTitle": "Игнориши",

internal/bootstrap/app_bootstrap.go

@@ -47,6 +47,10 @@ func (app *BootstrapApp) Setup() error {
 	fmt.Println("Tinyauth is moving to an organization! All versions after v5.0.7 will be released under ghcr.io/tinyauthapp/tinyauth. Existing images will continue to work but new features and updates (including security ones) will only be released under the new image path.")
 
 	// get app url
+	if app.config.AppURL == "" {
+		return fmt.Errorf("app URL cannot be empty, perhaps config loading failed")
+	}
+
 	appUrl, err := url.Parse(app.config.AppURL)
 
 	if err != nil {