feat(smurf-tf-drift): fix false drift detection and add env-specific alerts

[sunnymor-cd]

Description

Improves the shared smurf-tf-drift workflow to correctly detect actionable Terraform drift and avoid false positives when Terraform reports no infrastructure changes. Adds environment-aware issue and Slack notifications, configurable Slack alert titles, drift-related outputs, and improved drift handling for reusable single- and multi-environment workflows.

Type of Change

• 🐛 Bug fix
• ✨ New workflow
• 📝 Documentation update
• 🔧 Workflow enhancement
• 🎨 Code style/formatting
• ♻️ Refactoring
• ⚡ Performance improvement
• 🔒 Security improvement

Workflow Category

• Terraform (tf-*)
• CloudFormation (cf-*)
• Docker (docker-*)
• Helm (helm-*)
• PR Automation (pr-*)
• Security (security-*)
• Release (release-*)
• Notification (notify-*)
• AWS-specific (aws-*)
• GCP-specific (gcp-*)
• YAML Lint (yl-*)
• Other

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published

Testing

Tested the shared workflow using staging, prod-us, and prod-eu Terraform environments.

• Verified environments with No changes do not report drift.
• Verified actual actionable Terraform changes are detected as drift.
• Verified drift creates an environment-specific GitHub issue.
• Verified clean environments do not create or update drift issues.
• Verified Slack alerts are sent only for the affected environment.
• Verified Slack alerts include the configured title, environment, repository, branch, and workflow run URL.
• Verified multi-environment execution works correctly through a caller workflow matrix.
• Ran yamllint and fixed formatting and lint issues.

Screenshots/Documentation

Related Issues

Closes #

Additional Notes

The workflow remains reusable for both single-environment and multi-environment Terraform setups. Environment-specific values are provided by the caller, allowing the shared workflow to handle Terraform drift detection, GitHub issues, and Slack notifications consistently.