Update cloud deployment lesson plan with CI/CD, observability notes, and new cloud service mappings

Added VPC, secrets management, and CI/CD rows to cloud service mapping table.
Added GitHub Actions section (Part 6) with dual EC2/GCE deploy workflow and test job.
Added OTel vs CloudWatch comparison, Docker layer concept, storage note, DNS clarification,
SSH key setup for both AWS and GCP, and inline comments throughout code examples.
Moved lesson plan from attendabot frontend to curriculum directory. Reorganized drills.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: dsshimel