[Improvement]: Deployments don't use external repository and rebuild images instead

[bigbasti]

Existing issue

• I have searched the existing issues and found no duplicate.

Current behavior

I build my app's images using github actions and push them to GHCR.

Then i trigger a webhook on OpenShip to redeploy the app.

But instead of using the ghcr image links as defined in the docker-compose file OpenShip rebuild the image on the server - which takes quite some resources.

Proposed improvement

OpenShip should use the images as defined in the docker-compose file and download them from the remote repository.

Benefits

Less stress on the machine openship is running on

Additional context

No response

[Hydralerne]

Reviewed against current main (c6cd723f) and the bugfix integration branch. The shared Compose pipeline already treats a service with image: and no build:/inline build as a prebuilt registry image, and skips the source-build phase. I added regression coverage: the GHCR reference is preserved without a build; explicitly declaring both image and build still requests a build. All 27 Compose build tests pass.

Could you share the sanitized effective Compose service definition, including any override files and build fields, your Openship version, and the beginning of the deployment build log? Please remove credentials and secret environment values. Those details distinguish an image-only regression from an explicit build recipe or a mutable-tag refresh problem.

Leaving this open until the reported configuration is reproduced. The integration branch is feat/bugfix-integration-2026-09-15; main is unchanged.