feat: decouple httpbin deployment from prereq DSF into a separate Helmsman app

[bhumi46]

Background

Currently, httpbin is deployed as part of the prereq-dsf.yaml pre-install hook script. This couples httpbin to the prereq DSF lifecycle, making it difficult to manage, upgrade, or disable it independently.

Goal

Decouple httpbin deployment from the pre-install script and manage it as a separate Helmsman app within the DSF, so it:

• Has its own priority, namespace, and version control
• Can be enabled or disabled without modifying the prereq pre-install script
• Follows the same Helmsman app lifecycle as all other services

Acceptance Criteria

• httpbin is defined as a standalone app entry in the DSF (not triggered via pre-install script)
• Pre-install script no longer deploys httpbin
• Existing deployments are not broken by the change