[Feature Request] Integrate Network Connectivity Center (NCC) #58

Feature Description

Replace the use of shared VPC and VPC peering constructs with Network Connectivity Center (NCC) for centralized connectivity management.

Use Case

The current networking implementation does not leverage NCC, resulting in networking code that is split up by compliance regime rather than being a normalized, centralized capability.

Proposed Solution

Reformat the network portion of fast/stages to use NCC. Normalize the networking code so it is a single stage that takes the regime type (e.g., FedRAMP Moderate, IL5) as an input configuration variable.

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
• Relevant NIST 800-53r5 Controls: SC-7 (Boundary Protection).

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

Maintaining the current state where networking logic is duplicated and hardcoded across different regime-specific folders.

Additional Context

N/A