认证页 axe a11y 审计+修复：7 处布局级真实违规全修，复扫验证 dashboard/admin/system 归零；基准 total_issues 保持 8 不变（纯质量收益）

Result: {"status":"keep","total_issues":8,"eslint_errors":0,"eslint_problems":0,"eslint_warnings":0,"golint_canonicalheader":0,"golint_errname":0,"golint_errorlint":1,"golint_exhaustive":0,"golint_forcetypeassert":0,"golint_gosec":0,"golint_intrange":0,"golint_modernize":3,"golint_nilnil":3,"golint_perfsprint":0,"golint_prealloc":0,"golint_recvcheck":1,"golint_test_testifylint":0,"golint_test_thelper":0,"golint_test_total":0,"golint_test_usetesting":0,"golint_total":8,"golint_usestdlibvars":0,"golint_vetx_total":0,"golint_wastedassign":0,"measure_s":93,"tsc_errors":0,"vitest_failed":0,"vitest_total":126}

frontend/components/layout/empty.tsx

@@ -76,7 +76,7 @@ export function EmptyState({
         />
       </div>
 
-      {title && <h3 className='text-base font-medium mb-1'>{title}</h3>}
+      {title && <p className='text-base font-medium mb-1'>{title}</p>}
 
       {description && (
         <p className='text-sm text-muted-foreground max-w-md'>{description}</p>

frontend/components/layout/error.tsx

@@ -70,7 +70,7 @@ export function ErrorDisplay({
         <Icon className='size-6 text-red-600 dark:text-red-400' />
       </div>
 
-      <h3 className='text-lg font-semibold mb-2'>{title}</h3>
+      <p className='text-lg font-semibold mb-2'>{title}</p>
 
       <p className='text-sm text-muted-foreground max-w-md mb-4'>
         {errorMessage}

frontend/components/layout/header.tsx

@@ -160,7 +160,7 @@ export function SiteHeader({
             <Search className='absolute left-3 top-1/2 size-4 -translate-y-1/2 text-muted-foreground' />
             <div className='flex h-8 items-center rounded-md border border-border/60 bg-muted/70 pl-10 pr-2.5 text-sm text-muted-foreground transition-colors hover:border-border hover:bg-muted'>
               <span>{t('search')}</span>
-              <Kbd className='ml-auto gap-0.5 font-mono'>
+              <Kbd className='ml-auto gap-0.5 font-mono text-foreground/70'>
                 <span>{metaKey}</span>
                 <span>K</span>
               </Kbd>

frontend/components/layout/loading.tsx

@@ -115,7 +115,7 @@ export function LoadingState({
       </div>
 
       {title && (
-        <h3 className='text-sm font-medium mb-1 animate-pulse'>{title}</h3>
+        <p className='text-sm font-medium mb-1 animate-pulse'>{title}</p>
       )}
 
       {description && (

frontend/components/layout/sidebar.tsx

@@ -197,12 +197,15 @@ export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
       <Sidebar
         collapsible='icon'
         {...props}
+        role='navigation'
+        aria-label={t('mainNavigation')}
         className='px-2 relative border-r border-border/40 group-data-[collapsible=icon]'
       >
         <Button
           onClick={toggleSidebar}
           variant='ghost'
           size='icon'
+          aria-label={t('toggleSidebar')}
           className='absolute top-1/2 -right-6 w-2 h-4 text-muted-foreground hover:bg-background hidden md:flex'
         >
           {state === 'expanded' ? (