feat(ci): automate demo instance deploy #10887

[Abhishek9639]

Description

Adds a new workflow_dispatch workflow (deploy-demo.yml) that automates the manual demo instance upgrade during the release process. Instead of requiring a release engineer to have local kubectl/helm setup and EKS access, they can now just trigger this workflow from the Actions tab with a release tag.

The workflow handles:

• Staging the upgrade via /api/v2/upgrade/stage
• Polling until staging completes
• Configuring kubectl for the dev EKS cluster
• Downloading current values.yaml and updating cht_image_tag/chtversion
• Running helm upgrade
• Polling /api/v2/monitoring until the version matches
• Deploying demo config via the existing deploy-conf action

Also updated the major and patch release templates to reference the new workflow instead of listing ~10 manual sub-steps.

#10887

Code review checklist

• Readable: Naming, comments and structuring makes the code easy to understand
• Documented: Configuration and user documentation on cht-docs
• Backwards compatible: Works with existing data and configuration or includes a migration. Any breaking changes documented in the release notes.

License

The software is provided under AGPL-3.0. Contributions to this project are accepted under the same license.

[Abhishek9639]

Hi @jkuester, @sugat009 or @dianabarsan,
This PR automates the demo upgrade steps from the release checklist. The workflow covers staging, helm upgrade, monitoring poll, and cht-conf config upload basically replacing all the manual kubectl/helm steps with a single button click from the Actions tab.

One thing to note: the repo will need a few new secrets configured (DEMO_CHT_URL, DEMO_CHT_HOSTNAME, DEMO_CHT_USER, DEMO_CHT_PASS) before the workflow can actually run. The AWS/ECR secrets are already in place.

Happy to adjust anything based on your feedback. Let me know if the polling logic or timeout values need tweaking.
Thanks