OneClickAppDefinitionResponse types appTemplate as string, but backend returns an object

[githubsaturn]

The getOneClickAppByName SDK response model currently declares appTemplate: string, while the CapRover backend returns the parsed template object from /user/oneclick/template.

This forces consumers to cast through unknown before using the fetched template with startOneClickAppDeploy.

Observed while adding repository-backed one-click deployment coverage in caprover/caprover-e2e#36.

Suggested fix:

• Change OneClickAppDefinitionResponse.appTemplate to IOneClickTemplate.
• Add a contract test covering the response from getOneClickAppByName.
• Publish the corrected SDK type and then remove the temporary cast in the E2E test.