"Fix

[syu-toutousai]

• Replaces process_resident_memory_bytes / process_resident_memory_bytes > 0.9 with process_resident_memory_bytes / machine_memory_bytes > 0.9.
• Introduces robust PromQL validation check in upload_prometheus_rules to reject self-dividing expressions.
• Adds comprehensive unit test suite inside tools/test_monitoring_setup.py.
• Commits required diagnostic logd artifacts from build.py execution.

Summary

Changes

Testing

Checklist

• Relevant modules affected by these changes build locally
• Tests pass locally
• Diagnostic build log is committed in this PR
• Documentation has been updated, if applicable
• Configuration or schema changes are documented, if applicable
• No generated build artifacts are committed, except the required diagnostic build log
• Changes are scoped to the PR purpose and avoid unrelated cleanup
• Security, privacy, and error-handling implications have been considered

---

• I would like to request that my diagnostic build log is removed before merging