Issue is that grandine does not have a metric that shows the current slot based on genesis time and current time, which leaves us with these options:

• make a similar thing as for the execution clients (getting sync status via RPC) and use the beacon api
• • this can be done by calling an existing function to get the current slot
• • or by directly calling the /eth/v1/node/syncing endpoint
• wait for grandine to implement this metric
• just show 100% with beacon_head_slot to ensure sync status is loading at all

i went with the latest as implementing this would take me (and probably dave as well) quite some time