feat(help-center): support per-locale portal title, name & header (#14642)

Portals can now override their name, page title and header text per
locale, with a fallback chain of locale override → default locale → base
value. Overrides are stored under portal.config.locale_translations and
validated with a JSON schema.

Editing is exposed as a "Localize content" action in each non-default
locale's menu on the Locale page, and all public-facing portal views
(classic + documentation layouts) render the localized values. The live
chat widget is also loaded in the active portal locale.


<img width="494" height="395" alt="Screenshot 2026-06-03 at 2 48 59 PM"
src="https://github.com/user-attachments/assets/e55a06e8-f20f-4d8a-9352-92fde28a9a19"
/>



https://github.com/user-attachments/assets/f5affbd2-7ad4-415a-b376-57c759fc2aaa

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/javascript/dashboard/components-next/HelpCenter/LocaleCard/LocaleCard.vue

@@ -53,6 +53,9 @@ const localeMenuLabels = computed(() => ({
   'publish-locale': t(
     'HELP_CENTER.LOCALES_PAGE.LOCALE_CARD.DROPDOWN_MENU.PUBLISH_LOCALE'
   ),
+  'customize-content': t(
+    'HELP_CENTER.LOCALES_PAGE.LOCALE_CARD.DROPDOWN_MENU.CUSTOMIZE_CONTENT'
+  ),
   delete: t('HELP_CENTER.LOCALES_PAGE.LOCALE_CARD.DROPDOWN_MENU.DELETE'),
 }));
 
@@ -128,7 +131,7 @@ const handleAction = ({ action, value }) => {
           <DropdownMenu
             v-if="showDropdownMenu"
             :menu-items="localeMenuItems"
-            class="ltr:right-0 rtl:left-0 mt-1 xl:ltr:left-0 xl:rtl:right-0 top-full z-60 min-w-[150px]"
+            class="ltr:right-0 rtl:left-0 mt-1 top-full z-60 min-w-[150px]"
             @action="handleAction"
           />
         </div>