Refactor VPN configuration handling to remove device limit management

- Updated the VPN configuration commands and handlers to eliminate the device limit parameter, simplifying the configuration process.
- Adjusted related API documentation to reflect the removal of device limit management, clarifying that this setting is now handled directly in the 3x-ui by node administrators.
- Enhanced the overall codebase by removing unnecessary device limit references across various components, ensuring a cleaner and more maintainable code structure.

frontend/src/features/configs/CreateConfigDialog.tsx

@@ -18,17 +18,15 @@ export function CreateConfigDialog({ inbounds }: { inbounds: AvailableInboundDto
   const [open, setOpen] = useState(false)
   const [inboundId, setInboundId] = useState('')
   const [label, setLabel] = useState('')
-  const [deviceLimit, setDeviceLimit] = useState('')
 
   const createMutation = useMutation({
-    mutationFn: () => createConfig(inboundId, label.trim() || undefined, deviceLimit ? Number(deviceLimit) : undefined),
+    mutationFn: () => createConfig(inboundId, label.trim() || undefined),
     onSuccess: async () => {
       toast.success(t('configs.created'))
       await queryClient.invalidateQueries({ queryKey: ['my-configs'] })
       setOpen(false)
       setInboundId('')
       setLabel('')
-      setDeviceLimit('')
     },
     onError: (error) => {
       const message =
@@ -75,17 +73,6 @@ export function CreateConfigDialog({ inbounds }: { inbounds: AvailableInboundDto
             <Label htmlFor="label">{t('configs.label')}</Label>
             <Input id="label" value={label} onChange={(e) => setLabel(e.target.value)} />
           </div>
-          <div className="flex flex-col gap-1.5">
-            <Label htmlFor="deviceLimit">{t('configs.deviceLimitLabel')}</Label>
-            <Input
-              id="deviceLimit"
-              type="number"
-              min={0}
-              placeholder={t('configs.deviceLimitPlaceholder')}
-              value={deviceLimit}
-              onChange={(e) => setDeviceLimit(e.target.value)}
-            />
-          </div>
           <Button type="submit" disabled={!inboundId || createMutation.isPending}>
             {t('configs.create')}
           </Button>