fix: accessibility, query cache clear, post-merge navigation

- Add aria-hidden="true" to all decorative SVGs (TelegramIcon, EmailIcon
  in MergeAccounts + ConnectedAccounts, all 4 OAuthProviderIcon SVGs)
- Add role="radiogroup" with aria-label to subscription choice container
- Clear react-query cache after merge to prevent stale data
- Wrap checkAdminStatus() in try-catch to prevent throw after token set
- Navigate to /profile/accounts after merge instead of /
- Import useQueryClient for cache management

src/pages/ConnectedAccounts.tsx

@@ -17,7 +17,7 @@ const isOAuthProvider = (provider: string): boolean => OAUTH_PROVIDERS.includes(
 // Icons for providers not covered by OAuthProviderIcon
 function TelegramIcon({ className = 'h-5 w-5' }: { className?: string }) {
   return (
-    <svg className={className} viewBox="0 0 24 24">
+    <svg className={className} viewBox="0 0 24 24" aria-hidden="true">
       <path
         d="M12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm4.64 6.8c-.15 1.58-.8 5.42-1.13 7.19-.14.75-.42 1-.68 1.03-.58.05-1.02-.38-1.58-.75-.88-.58-1.38-.94-2.23-1.5-.99-.65-.35-1.01.22-1.59.15-.15 2.71-2.48 2.76-2.69.01-.03.01-.14-.07-.2-.08-.06-.19-.04-.28-.02-.12.03-2.02 1.28-5.69 3.77-.54.37-1.03.55-1.47.54-.48-.01-1.41-.27-2.1-.5-.85-.28-1.52-.43-1.46-.91.03-.25.38-.51 1.05-.78 4.12-1.79 6.87-2.97 8.26-3.54 3.93-1.62 4.75-1.9 5.28-1.91.12 0 .37.03.54.17.14.12.18.28.2.46-.01.06.01.24 0 .37z"
         fill="#29B6F6"
@@ -34,6 +34,7 @@ function EmailIcon({ className = 'h-5 w-5' }: { className?: string }) {
       viewBox="0 0 24 24"
       stroke="currentColor"
       strokeWidth={1.5}
+      aria-hidden="true"
     >
       <path
         strokeLinecap="round"