dashdot: [Bug] Support for deployment on Synology NAS

Description of the bug

New installation with deployment of a Portainer stack : widget storage not working.

version: "3.9"
services:
  dashdot:
    container_name: dashdot
    image: mauricenino/dashdot:latest
    mem_limit: 4g
    cpu_shares: 768
    security_opt:
      - no-new-privileges:true
    restart: on-failure:5
    volumes:
      - /:/mnt/host:ro
    ports:
      - 7512:3001
    privileged: true
    environment:
      DASHDOT_ENABLE_CPU_TEMPS: true
      DASHDOT_ALWAYS_SHOW_PERCENTAGES: true
      DASHDOT_CUSTOM_HOST: 
      DASHDOT_SHOW_HOST: true
      DASHDOT_PAGE_TITLE: 
      DASHDOT_SHOW_DASH_VERSION: icon_hover
      DASHDOT_ACCEPT_OOKLA_EULA: true

Relevant log output

/app # df                                                                        
Filesystem           1K-blocks      Used Available Use% Mounted on               
/dev/vg1/volume_1    3746086260 3527720912 218365348  94% /                      
tmpfs                    65536         0     65536   0% /dev                     
tmpfs                  2962468         0   2962468   0% /sys/fs/cgroup           
shm                      65536         0     65536   0% /dev/shm                 
/dev/md0               2385528   1548928    717816  68% /mnt/host                
tmpfs                  2962468         0   2962468   0% /mnt/host/sys/fs/cgroup  
devtmpfs               2958988         0   2958988   0% /mnt/host/proc/bus/usb   
devtmpfs               2958988         0   2958988   0% /mnt/host/dev            
tmpfs                  2962468       380   2962088   0% /mnt/host/dev/shm        
tmpfs                  2962468     36996   2925472   1% /mnt/host/run            
tmpfs                   592496         0    592496   0% /mnt/host/run/user/196791
tmpfs                  2962468      1548   2960920   0% /mnt/host/tmp            
/dev/vg1/volume_1    3746086260 3527720912 218365348  94% /mnt/host/volume1      
df: /mnt/host/volume1/RT2600acVB/Clé\040USB: No such file or directory           
df: /mnt/host/volume1/RT2600acVB/Carte\040SD: No such file or directory          
/dev/vg1/volume_1    3746086260 3527720912 218365348  94% /mnt/host/volume1/@dock
er                                                                               
/dev/vg1/volume_1    3746086260 3527720912 218365348  94% /mnt/host/volume1/@dock
er/btrfs                                                                         
/dev/vg1/volume_1    3746086260 3527720912 218365348  94% /mnt/host/volume1/@dock
er/btrfs/subvolumes/cbb0ef0ca8372f873d511b6ff6c3a2973b8e3debf88efd59cd585e1f91ea8
ba3                                                                              
tmpfs                    65536         0     65536   0% /mnt/host/volume1/@docker
/btrfs/subvolumes/cbb0ef0ca8372f873d511b6ff6c3a2973b8e3debf88efd59cd585e1f91ea8ba
3/dev                                                                            

What browsers are you seeing the problem on?

Firefox, Safari

Where is your instance running?

Container Manager DSM 7.2.1-69057 Update 1