refactor: update existing grafana alerts

[amdove]

Description

No changes to functionality, only Grafana alert configuration and format as follows.

Severity adjustments:

• Loki WAL alert: CRITICAL → WARNING
• CrashLoopBackoff: CRITICAL → WARNING
• Node Not Ready: CRITICAL → WARNING

FSx alerts:

• Split single alert into warning (80%) and critical (90%) thresholds

CloudWatch cleanup:

• Removed EC2 NetworkOut and NetworkPacketsOut alerts (low signal, high noise)

Pod alerts cleanup:

• Removed PodError, PodNotHealthy, and PodRestarts

RDS alerts:

• Updated CPU utilization alert (80% threshold)
• Split storage into warning (10 GiB) and critical (5 GiB); removed old single-threshold alert
• Updated freeable memory threshold (512 MiB → 256 MiB) and unpaused
• Removed read latency alert

Load balancer alerts:

• Standardized annotation format to match other alerts (WHERE/DETAILS sections)

Node alerts:

• Added comment header template for consistency

RDS storage thresholds:

• Uses static thresholds rather than percentage-based because CloudWatch only exposes FreeStorageSpace, not total allocated storage.

Category of change

• Bug fix (non-breaking change which fixes an issue)
• Version upgrade (upgrading the version of a service or product)
• New feature (non-breaking change which adds functionality)
• Build: a code change that affects the build system or external dependencies
• Performance: a code change that improves performance
• Refactor: a code change that neither fixes a bug nor adds a feature
• Documentation: documentation changes
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have reviewed my own diff and added inline comments on lines I want reviewers to focus on or that I am uncertain about

[stevenolen]

🎉