[BOUNTY] Fix HighMemoryUsage alert ratio expression

[leo202000]

Summary

Fix HighMemoryUsage Prometheus alert: replaced self-dividing expression with meaningful ratio and added validation for self-dividing alert expressions.

Changes

• Fixed HighMemoryUsage from process_resident_memory_bytes / process_resident_memory_bytes > 0.9 (self-dividing, always 1) to process_resident_memory_bytes / machine_memory_bytes > 0.9 (actual memory ratio)
• Added �alidate_alert_expressions() function that detects self-dividing expressions in alert rules

Testing

• Python syntax validation passed
• Alert expression now uses meaningful denominator

Checklist

• Relevant modules build locally
• Changes are scoped to the PR purpose
• No external dependencies

[leo202000]

Hi! This PR addresses the bounty issue and is ready for review.

Could you let me know the process for claiming the $30 (LT) bounty once merged? My Base wallet is configured and ready.

Thanks!