feat: add registration invite code handling and improve error translations

- Updated AuthViews component to conditionally show invite code field based on registrationInviteRequired prop.
- Enhanced error handling in auth API functions to use translateServerError for better user feedback.
- Added new translations for various server error messages in English, Spanish, Russian, Chinese (Simplified and Traditional).
- Modified demo initial bootstrap state to include registrationInviteRequired flag.
- Updated types to include registrationInviteRequired in WebBootstrapResponse.

webapp/src/components/AuthViews.tsx

@@ -27,6 +27,7 @@ interface AuthViewsProps {
   unlockPreparing: boolean;
   loginValues: LoginValues;
   registerValues: RegisterValues;
+  registrationInviteRequired?: boolean;
   unlockPassword: string;
   emailForLock: string;
   loginHintLoading: boolean;
@@ -77,6 +78,7 @@ export default function AuthViews(props: AuthViewsProps) {
   const loginBusy = props.pendingAction === 'login';
   const registerBusy = props.pendingAction === 'register';
   const unlockBusy = props.pendingAction === 'unlock';
+  const showInviteCodeField = props.registrationInviteRequired !== false || !!props.registerValues.inviteCode.trim();
 
   if (props.mode === 'locked') {
     return (
@@ -184,17 +186,19 @@ export default function AuthViews(props: AuthViewsProps) {
                 }
               />
             </label>
-            <label className="field">
-              <span>{t('txt_invite_code_optional')}</span>
-              <input
-                className="input"
-                value={props.registerValues.inviteCode}
-                autoComplete="off"
-                onInput={(e) =>
-                  props.onChangeRegister({ ...props.registerValues, inviteCode: (e.currentTarget as HTMLInputElement).value })
-                }
-              />
-            </label>
+            {showInviteCodeField ? (
+              <label className="field">
+                <span>{t('txt_invite_code_required')}</span>
+                <input
+                  className="input"
+                  value={props.registerValues.inviteCode}
+                  autoComplete="off"
+                  onInput={(e) =>
+                    props.onChangeRegister({ ...props.registerValues, inviteCode: (e.currentTarget as HTMLInputElement).value })
+                  }
+                />
+              </label>
+            ) : null}
             <button type="submit" className="btn btn-primary full" disabled={registerBusy}>
               <UserPlus size={16} className="btn-icon" />
               {registerBusy ? t('txt_registering') : t('txt_create_account')}