feat: Complete PII cleanup and fully automatic pipeline

🧹 PII Cleanup & Security:
- Remove all hardcoded domains (darknex.us, hndrx.co)
- Remove all hardcoded emails (admin@ references)
- Replace all personal info with environment variables
- Repository now 100% generic and reusable

🚀 Fully Automatic Pipeline:
- Pipeline now runs automatically develop → staging → production
- No manual intervention required for production promotions
- Auto-promotion triggers after successful tests
- All workflows use commit-specific image tags

🔧 Environment Variables:
- All manifests use ${VARIABLE_NAME} syntax
- All scripts source from .env file
- GitHub Actions use secrets for sensitive data
- Complete .env.example template provided

📚 Documentation:
- New comprehensive WORKFLOWS.md with pipeline details
- New PIPELINE_QUICK_REFERENCE.md for quick reference
- Updated all docs to use generic placeholders
- Added security/privacy section to README

🔐 Security Enhancements:
- Updated .gitignore for all sensitive files
- Created PII verification script (verify-pii-removal.sh)
- Created cleanup automation script (cleanup-pii.sh)
- Repository verified PII-free and production-ready

BREAKING: Repository now requires .env configuration
- Copy .env.example to .env and configure for your environment
- Set GitHub repository secrets for CI/CD workflows
- All deployments now use environment-specific configuration

manifests/prod/service.yml

@@ -15,7 +15,7 @@ spec:
         autoscaling.knative.dev/target: "100"
     spec:
       containers:
-      - image: ghcr.io/ghndrx/k8s-game-2048:latest
+      - image: ${CONTAINER_REGISTRY}/${GITHUB_REPOSITORY}:latest
         imagePullPolicy: Always
         ports:
         - containerPort: 80