Uptime reports

[nrutledge]

We need to be able to provide evidence that the testnet has been up and running with at least 99% uptime.

Acceptance Criteria

• [ ] The report/dashboard is publicly accessible
• [ ] Granular history for the current day is shown
• [ ] Average uptime for at least the last 6 months can be viewed

[nrutledge]

Further discussion on Slack: https://mlabs-corp.slack.com/archives/C0602K159NU/p1710523855297219