✨ refactor: system settings UI for consistent, compact layouts

Redesign the system settings interface to align with the rest of the console experience by using fixed header actions, removing redundant subtitles, respecting global content width, and standardizing responsive form layouts.

Introduce reusable settings layout primitives for forms, switch rows, grouped controls, nested control sections, title status indicators, and page action portals. Replace duplicated card-style switch markup with explicit compact components, improve nested switch readability, and reduce visual noise across authentication, billing, content, integrations, maintenance, models, and request-limit settings.

Also complete missing i18n translations, remove obsolete subtitle translation keys, refine i18n sync reporting, fix sidebar truncation for long labels, and verify the frontend with type checking and lint diagnostics.

web/default/src/features/system-settings/site/section-registry.tsx

@@ -33,7 +33,6 @@ const SITE_SECTIONS = [
   {
     id: 'system-info',
     titleKey: 'System Information',
-    descriptionKey: 'Configure basic system information and branding',
     build: (settings: SiteSettings) => (
       <SystemInfoSection
         defaultValues={{
@@ -57,7 +56,6 @@ const SITE_SECTIONS = [
   {
     id: 'notice',
     titleKey: 'System Notice',
-    descriptionKey: 'Configure system maintenance notice',
     build: (settings: SiteSettings) => (
       <NoticeSection defaultValue={settings.Notice ?? ''} />
     ),
@@ -65,7 +63,6 @@ const SITE_SECTIONS = [
   {
     id: 'header-navigation',
     titleKey: 'Header navigation',
-    descriptionKey: 'Configure header navigation modules',
     build: (settings: SiteSettings) => {
       const headerNavConfig = parseHeaderNavModules(settings.HeaderNavModules)
       const headerNavSerialized = serializeHeaderNavModules(headerNavConfig)
@@ -80,7 +77,6 @@ const SITE_SECTIONS = [
   {
     id: 'sidebar-modules',
     titleKey: 'Sidebar modules',
-    descriptionKey: 'Configure sidebar modules for admin',
     build: (settings: SiteSettings) => {
       const sidebarConfig = parseSidebarModulesAdmin(
         settings.SidebarModulesAdmin
@@ -109,3 +105,4 @@ export const SITE_SECTION_IDS = siteRegistry.sectionIds
 export const SITE_DEFAULT_SECTION = siteRegistry.defaultSection
 export const getSiteSectionNavItems = siteRegistry.getSectionNavItems
 export const getSiteSectionContent = siteRegistry.getSectionContent
+export const getSiteSectionMeta = siteRegistry.getSectionMeta