docs: remove outdated metadata files and update README with new demo GIF

lib/l10n/app_localizations.dart

@@ -404,19 +404,43 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'Username or Email'**
   String get usernameOrEmail;
-
+  
   /// No description provided for @password.
   ///
   /// In en, this message translates to:
   /// **'Password'**
   String get password;
 
+  /// No description provided for @usernameOrEmailHint.
+  ///
+  /// In en, this message translates to:
+  /// **'Enter your username or email'**
+  String get usernameOrEmailHint;
+
+  /// No description provided for @passwordHint.
+  ///
+  /// In en, this message translates to:
+  /// **'Enter your password'**
+  String get passwordHint;
+
   /// No description provided for @signInWithApiKey.
   ///
   /// In en, this message translates to:
   /// **'Sign in with API Key'**
   String get signInWithApiKey;
 
+  /// No description provided for @enterApiKey.
+  ///
+  /// In en, this message translates to:
+  /// **'Enter your API key'**
+  String get enterApiKey;
+
+  /// No description provided for @signingIn.
+  ///
+  /// In en, this message translates to:
+  /// **'Signing in...'**
+  String get signingIn;
+
   /// No description provided for @connectToServer.
   ///
   /// In en, this message translates to:
@@ -483,6 +507,84 @@ abstract class AppLocalizations {
   /// **'Remove header'**
   String get removeHeader;
 
+  /// No description provided for @advancedSettings.
+  ///
+  /// In en, this message translates to:
+  /// **'Advanced Settings'**
+  String get advancedSettings;
+
+  /// No description provided for @customHeaders.
+  ///
+  /// In en, this message translates to:
+  /// **'Custom Headers'**
+  String get customHeaders;
+
+  /// No description provided for @customHeadersDescription.
+  ///
+  /// In en, this message translates to:
+  /// **'Add custom HTTP headers for authentication, API keys, or special server requirements.'**
+  String get customHeadersDescription;
+
+  /// No description provided for @headerNameEmpty.
+  ///
+  /// In en, this message translates to:
+  /// **'Header name cannot be empty'**
+  String get headerNameEmpty;
+
+  /// No description provided for @headerNameTooLong.
+  ///
+  /// In en, this message translates to:
+  /// **'Header name too long (max 64 characters)'**
+  String get headerNameTooLong;
+
+  /// No description provided for @headerNameInvalidChars.
+  ///
+  /// In en, this message translates to:
+  /// **'Invalid header name. Use only letters, numbers, and these symbols: !#\$&-^_`|~'**
+  String get headerNameInvalidChars;
+
+  /// No description provided for @headerNameReserved.
+  ///
+  /// In en, this message translates to:
+  /// **'Cannot override reserved header "{key}"'**
+  String headerNameReserved(String key);
+
+  /// No description provided for @headerValueEmpty.
+  ///
+  /// In en, this message translates to:
+  /// **'Header value cannot be empty'**
+  String get headerValueEmpty;
+
+  /// No description provided for @headerValueTooLong.
+  ///
+  /// In en, this message translates to:
+  /// **'Header value too long (max 1024 characters)'**
+  String get headerValueTooLong;
+
+  /// No description provided for @headerValueInvalidChars.
+  ///
+  /// In en, this message translates to:
+  /// **'Header value contains invalid characters. Use only printable ASCII.'**
+  String get headerValueInvalidChars;
+
+  /// No description provided for @headerValueUnsafe.
+  ///
+  /// In en, this message translates to:
+  /// **'Header value appears to contain potentially unsafe content'**
+  String get headerValueUnsafe;
+
+  /// No description provided for @headerAlreadyExists.
+  ///
+  /// In en, this message translates to:
+  /// **'Header "{key}" already exists. Remove it first to update.'**
+  String headerAlreadyExists(String key);
+
+  /// No description provided for @maxHeadersReachedDetail.
+  ///
+  /// In en, this message translates to:
+  /// **'Maximum of 10 custom headers allowed. Remove some to add more.'**
+  String get maxHeadersReachedDetail;
+  
   /// No description provided for @connecting.
   ///
   /// In en, this message translates to:

lib/l10n/app_localizations_de.dart

@@ -177,9 +177,21 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get password => 'Passwort';
 
+  @override
+  String get usernameOrEmailHint => 'Gib deinen Benutzernamen oder deine E‑Mail ein';
+
+  @override
+  String get passwordHint => 'Gib dein Passwort ein';
+
   @override
   String get signInWithApiKey => 'Mit API-Schlüssel anmelden';
 
+  @override
+  String get enterApiKey => 'Gib deinen API-Schlüssel ein';
+  
+  @override
+  String get signingIn => 'Anmeldung läuft...';
+
   @override
   String get connectToServer => 'Mit Server verbinden';
 
@@ -213,6 +225,51 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get removeHeader => 'Header entfernen';
 
+  @override
+  String get advancedSettings => 'Erweiterte Einstellungen';
+
+  @override
+  String get customHeaders => 'Benutzerdefinierte Header';
+
+  @override
+  String get customHeadersDescription =>
+      'Füge benutzerdefinierte HTTP-Header für Authentifizierung, API-Schlüssel oder spezielle Serveranforderungen hinzu.';
+
+  @override
+  String get headerNameEmpty => 'Header-Name darf nicht leer sein';
+
+  @override
+  String get headerNameTooLong => 'Header-Name zu lang (max. 64 Zeichen)';
+
+  @override
+  String get headerNameInvalidChars =>
+      'Ungültiger Header-Name. Verwende nur Buchstaben, Zahlen und diese Symbole: !#\$&-^_`|~';
+
+  @override
+  String headerNameReserved(String key) => 'Reservierter Header "$key" kann nicht überschrieben werden';
+
+  @override
+  String get headerValueEmpty => 'Header-Wert darf nicht leer sein';
+
+  @override
+  String get headerValueTooLong => 'Header-Wert zu lang (max. 1024 Zeichen)';
+
+  @override
+  String get headerValueInvalidChars =>
+      'Header-Wert enthält ungültige Zeichen. Verwende nur druckbare ASCII-Zeichen.';
+
+  @override
+  String get headerValueUnsafe =>
+      'Header-Wert scheint potenziell unsicheren Inhalt zu enthalten';
+
+  @override
+  String headerAlreadyExists(String key) =>
+      'Header "$key" existiert bereits. Entferne ihn zuerst, um ihn zu aktualisieren.';
+
+  @override
+  String get maxHeadersReachedDetail =>
+      'Maximal 10 benutzerdefinierte Header erlaubt. Entferne einige, um weitere hinzuzufügen.';
+
   @override
   String get connecting => 'Verbindung wird hergestellt...';
 

lib/l10n/app_localizations_en.dart

@@ -177,9 +177,21 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get password => 'Password';
 
+  @override
+  String get usernameOrEmailHint => 'Enter your username or email';
+
+  @override
+  String get passwordHint => 'Enter your password';
+
   @override
   String get signInWithApiKey => 'Sign in with API Key';
 
+  @override
+  String get enterApiKey => 'Enter your API key';
+  
+  @override
+  String get signingIn => 'Signing in...';
+
   @override
   String get connectToServer => 'Connect to Server';
 
@@ -213,6 +225,51 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get removeHeader => 'Remove header';
 
+  @override
+  String get advancedSettings => 'Advanced Settings';
+
+  @override
+  String get customHeaders => 'Custom Headers';
+
+  @override
+  String get customHeadersDescription =>
+      'Add custom HTTP headers for authentication, API keys, or special server requirements.';
+
+  @override
+  String get headerNameEmpty => 'Header name cannot be empty';
+
+  @override
+  String get headerNameTooLong => 'Header name too long (max 64 characters)';
+
+  @override
+  String get headerNameInvalidChars =>
+      'Invalid header name. Use only letters, numbers, and these symbols: !#\$&-^_`|~';
+
+  @override
+  String headerNameReserved(String key) => 'Cannot override reserved header "$key"';
+
+  @override
+  String get headerValueEmpty => 'Header value cannot be empty';
+
+  @override
+  String get headerValueTooLong => 'Header value too long (max 1024 characters)';
+
+  @override
+  String get headerValueInvalidChars =>
+      'Header value contains invalid characters. Use only printable ASCII.';
+
+  @override
+  String get headerValueUnsafe =>
+      'Header value appears to contain potentially unsafe content';
+
+  @override
+  String headerAlreadyExists(String key) =>
+      'Header "$key" already exists. Remove it first to update.';
+
+  @override
+  String get maxHeadersReachedDetail =>
+      'Maximum of 10 custom headers allowed. Remove some to add more.';
+
   @override
   String get connecting => 'Connecting...';
 

lib/l10n/app_localizations_fr.dart

@@ -177,9 +177,21 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get password => 'Mot de passe';
 
+  @override
+  String get usernameOrEmailHint => 'Entrez votre nom d\'utilisateur ou e‑mail';
+
+  @override
+  String get passwordHint => 'Entrez votre mot de passe';
+
   @override
   String get signInWithApiKey => 'Se connecter avec une clé API';
 
+  @override
+  String get enterApiKey => 'Entrez votre clé API';
+  
+  @override
+  String get signingIn => 'Connexion en cours...';
+
   @override
   String get connectToServer => 'Se connecter au serveur';
 
@@ -213,6 +225,53 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get removeHeader => 'Supprimer l\'en-tête';
 
+  @override
+  String get advancedSettings => 'Paramètres avancés';
+
+  @override
+  String get customHeaders => 'En-têtes personnalisés';
+
+  @override
+  String get customHeadersDescription =>
+      'Ajoutez des en-têtes HTTP personnalisés pour l\'authentification, les clés API ou des exigences spécifiques du serveur.';
+
+  @override
+  String get headerNameEmpty => 'Le nom de l\'en-tête ne peut pas être vide';
+
+  @override
+  String get headerNameTooLong => 'Nom d\'en-tête trop long (max 64 caractères)';
+
+  @override
+  String get headerNameInvalidChars =>
+      'Nom d\'en-tête invalide. Utilisez uniquement des lettres, des chiffres et ces symboles : !#\$&-^_`|~';
+
+  @override
+  String headerNameReserved(String key) =>
+      'Impossible d\'écraser l\'en-tête réservé « $key »';
+
+  @override
+  String get headerValueEmpty => 'La valeur de l\'en-tête ne peut pas être vide';
+
+  @override
+  String get headerValueTooLong =>
+      'Valeur d\'en-tête trop longue (max 1024 caractères)';
+
+  @override
+  String get headerValueInvalidChars =>
+      'La valeur de l\'en-tête contient des caractères invalides. Utilisez uniquement des caractères ASCII imprimables.';
+
+  @override
+  String get headerValueUnsafe =>
+      'La valeur de l\'en-tête semble contenir du contenu potentiellement dangereux';
+
+  @override
+  String headerAlreadyExists(String key) =>
+      'L\'en-tête « $key » existe déjà. Supprimez-le d\'abord pour le modifier.';
+
+  @override
+  String get maxHeadersReachedDetail =>
+      'Maximum 10 en-têtes personnalisés. Supprimez-en pour en ajouter.';
+
   @override
   String get connecting => 'Connexion en cours...';
 

lib/l10n/app_localizations_it.dart

@@ -177,9 +177,21 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get password => 'Password';
 
+  @override
+  String get usernameOrEmailHint => 'Inserisci il tuo username o e‑mail';
+
+  @override
+  String get passwordHint => 'Inserisci la password';
+
   @override
   String get signInWithApiKey => 'Accedi con chiave API';
 
+  @override
+  String get enterApiKey => 'Inserisci la tua chiave API';
+  
+  @override
+  String get signingIn => 'Accesso in corso...';
+
   @override
   String get connectToServer => 'Connetti al server';
 
@@ -213,6 +225,52 @@ class AppLocalizationsIt extends AppLocalizations {
   @override
   String get removeHeader => 'Rimuovi header';
 
+  @override
+  String get advancedSettings => 'Impostazioni avanzate';
+
+  @override
+  String get customHeaders => 'Header personalizzati';
+
+  @override
+  String get customHeadersDescription =>
+      'Aggiungi header HTTP personalizzati per autenticazione, chiavi API o requisiti speciali del server.';
+
+  @override
+  String get headerNameEmpty => 'Il nome header non può essere vuoto';
+
+  @override
+  String get headerNameTooLong => 'Nome header troppo lungo (max 64 caratteri)';
+
+  @override
+  String get headerNameInvalidChars =>
+      'Nome header non valido. Usa solo lettere, numeri e questi simboli: !#\$&-^_`|~';
+
+  @override
+  String headerNameReserved(String key) =>
+      'Impossibile sovrascrivere l\'header riservato "$key"';
+
+  @override
+  String get headerValueEmpty => 'Il valore header non può essere vuoto';
+
+  @override
+  String get headerValueTooLong => 'Valore header troppo lungo (max 1024 caratteri)';
+
+  @override
+  String get headerValueInvalidChars =>
+      'Il valore header contiene caratteri non validi. Usa solo ASCII stampabile.';
+
+  @override
+  String get headerValueUnsafe =>
+      'Il valore header sembra contenere contenuto potenzialmente non sicuro';
+
+  @override
+  String headerAlreadyExists(String key) =>
+      'L\'header "$key" esiste già. Rimuovilo prima per aggiornarlo.';
+
+  @override
+  String get maxHeadersReachedDetail =>
+      'Massimo 10 header personalizzati consentiti. Rimuovine alcuni per aggiungerne altri.';
+
   @override
   String get connecting => 'Connessione in corso...';