[Feature Request] Move self-managed SSL Certificate uploads to Terraform for G4G deployments

## Feature Description
Move self-managed SSL Certificate uploads for G4G from the helper utility function to Terraform.

## Use Case
Improves the deployment UX by reducing the number of manual steps as well as consolidates more deployment code into Terraform following best practices.

## Proposed Solution
Update Stage 1 of the `deploy.sh` script to prompt the user for the certificate name and the path to the SSL certificate. In the `gemini-stage-1` deployment code provision the self-managed certificate and attach it to the load balancer.

## Compliance & Deployment Context
* **Target Deployment Type(s):**
* [ ] US Region Restricted (e.g., Access Policy constraint)
* [ ] FedRAMP Medium
* [ ] FedRAMP High
* [ ] DoD IL4
* [ ] DoD IL5
* [x] All / General
* **Relevant NIST 800-53r5 Controls:** (If applicable, list the controls this feature helps satisfy)

## Reusability Check
Stellar Engine prioritizes reusability.
* [x] I have checked if this functionality can be achieved by extending an existing module or blueprint.
* [x] I have verified that this does not duplicate existing functionality.

Start with Stage 1 of deploy.sh and the gemini-stage-1 deployment code, then trace the existing helper utility used for self-managed SSL certificate uploads. Update the deployment flow to collect the certificate name and path, provision the certificate, and attach it to the load balancer; verify the general deployment path completes without the former manual upload step.

Written by the indexing model from the issue text.