Add monitoring for the shared wallet balance

[BigLep]

Done Criteria

We have automated alerting when the pin.filecoin.cloud balance gets low.
There is operational documentation about how/where it's configured.

Why Important

If it gets too low, the site breaks.

Notes

1. This is a good forcing function on our operational posture as it ensure we have the infrastructure for running checks, reporting the results, and alarming on the results.
2. Because this relies on infrastructure that a team (presumably FilOz) owns, this likely needs to be picked up by that team.

[SgtPooki]

I think we should solve this with https://www.notion.so/filecoindev/Mini-Design-Doc-Centralized-Wallet-Observability-Service-Proposal-2c4dc41950c180d484aad4f71ea85907 since we need to do it for dealbot too

[rjan90]

I started a shared dashboard for monitoring wallet balances:

Calibnet: https://telemetry.betterstack.com/team/t468215/dashboards/889002?rf=now-14d&rt=now&top=0

• Dealbot ✅ / Filecoin-Pin (TBD)