- adds disk IO
- removes error rate (its in the first row in the second section anyway)
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
## Release Notes
* **New Features**
* Added Disk IO metric card to monitor disk input/output performance in
real-time.
* **Changes**
* Removed Error Rate metric from database infrastructure monitoring
dashboard.
* Renamed "Disk" metric to "Disk Usage" for improved clarity.
* Enhanced disk metrics with refined measurements and calculations.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Observability Dashboard: unified overview for service health and
database infrastructure with interactive charts and metric cards (CPU,
memory, disk I/O, connections, error rate, slow queries).
* Service Health Monitoring: per-service health cards and a
multi-service table with error/warning counts and drill-down links to
reports/logs.
* Interval Selector: new chart-interval dropdown with plan-aware
retention messaging.
* Menu & Reports: updated Observability menu with Overview entry and
Custom Reports management.
* **Documentation**
* Added a footer link to troubleshooting guides.
<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Charis