feat: Add configurable maximum email limit for users

app/components/emails/email-list.tsx

@@ -49,9 +49,22 @@ export function EmailList({ onEmailSelect, selectedEmailId }: EmailListProps) {
   const [nextCursor, setNextCursor] = useState<string | null>(null)
   const [loadingMore, setLoadingMore] = useState(false)
   const [total, setTotal] = useState(0)
+  const [maxEmails, setMaxEmails] = useState<number>(EMAIL_CONFIG.MAX_ACTIVE_EMAILS)
   const [emailToDelete, setEmailToDelete] = useState<Email | null>(null)
   const { toast } = useToast()
 
+  const fetchMaxEmails = async () => {
+    try {
+      const res = await fetch("/api/config")
+      if (res.ok) {
+        const data = await res.json() as { maxEmails: string }
+        setMaxEmails(Number(data.maxEmails))
+      }
+    } catch (error) {
+      console.error("Failed to fetch max emails:", error)
+    }
+  }
+
   const fetchEmails = async (cursor?: string) => {
     try {
       const url = new URL("/api/emails", window.location.origin)
@@ -112,6 +125,9 @@ export function EmailList({ onEmailSelect, selectedEmailId }: EmailListProps) {
 
   useEffect(() => {
     if (session) fetchEmails()
+    if (session && role !== ROLES.EMPEROR) {
+      fetchMaxEmails()
+    }
   // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [session])
 
@@ -173,7 +189,7 @@ export function EmailList({ onEmailSelect, selectedEmailId }: EmailListProps) {
               {role === ROLES.EMPEROR ? (
                 `${total}/∞ 个邮箱`
               ) : (
-                `${total}/${EMAIL_CONFIG.MAX_ACTIVE_EMAILS} 个邮箱`
+                `${total}/${maxEmails} 个邮箱`
               )}
             </span>
           </div>