[Feature Request] Automate `backend.tf` state bucket substitutions

[aghassemlouei]

Feature Description

Automate the injection of state bucket names into backend.tf files.

Use Case

During the bootstrap phase, developers are currently forced to run manual command-line sed replacements to swap out UPDATE_ME placeholders with actual bucket names.

Proposed Solution

Develop a lightweight Go or Bash pre-flight script to handle variable substitution in backend.tf files dynamically before terraform init is run.

Compliance & Deployment Context

• Target Deployment Type(s):
  • US Region Restricted (e.g., Access Policy constraint)
  • FedRAMP Medium
  • FedRAMP High
  • DoD IL4
  • DoD IL5
  • All / General

Reusability Check

Stellar Engine prioritizes reusability.

• I have checked if this functionality can be achieved by extending an existing module or blueprint.
• I have verified that this does not duplicate existing functionality.

Alternatives Considered

Keeping the manual sed instructions in the README, which leads to user error.

Additional Context

This was explicitly requested in the legacy Feature Braindump from 2023.