fix(labs): validate and align Argo Events labs with official docs

[msahihi]

Summary

Comprehensive validation and alignment of all 4 Argo Events labs with official documentation at https://argoproj.github.io/argo-events/

Validated with Argo Events v1.9.10 and tested step-by-step on ARM64 (Apple Silicon).

Changes

Lab 01: Installation and Basics

• ✅ Add complete RBAC configuration (ServiceAccount, Role, RoleBinding)
• ✅ Add validating webhook installation (production best practice)
• ✅ Fix ARM64 compatibility (replace docker/whalesay with alpine)
• ✅ Update expected outputs for modern Argo Events v1.9+
• ✅ Align terminology with official docs (transport layer, publish-subscribe pattern)
• ✅ Document all 20+ EventSource types and trigger options

Labs 02-04: Event Sources, Triggers, Integration

• ✅ Add serviceAccountName to 16 sensors that create workflows
• ✅ Add version headers (v1.9+) to all labs
• ✅ Ensure RBAC alignment across all labs

Testing

• Lab 01 validated step-by-step with actual kubectl commands
• EventBus creation verified with 3 NATS replicas
• RBAC tested - workflows successfully created from webhook events
• All 4 lab files pass markdownlint (0 errors)
• Content aligned with official Argo Events documentation

Key Fixes

1. RBAC Configuration: Added missing ServiceAccount, Role, and RoleBinding required for sensors to create workflows
2. ARM64 Support: Replaced incompatible docker/whalesay image with alpine
3. Official Alignment: Updated all terminology to match official documentation
4. Version Clarity: Added version headers to all labs

Documentation

All changes follow the official Argo Events documentation and best practices from https://argoproj.github.io/argo-events/