chore(ci): rename docker image from lobstr-swa to lobstr

[Ryback2501]

Summary

• Rename the Docker image from lobstr-swa to lobstr across CI, the release workflow, and the Makefile, since the SWA is named Lobstr.

Changes

CI / build

• .github/workflows/ci-jobs.yml — docker-smoke job builds lobstr:ci, runs container lobstr, and references lobstr in the healthcheck logs and teardown.
• .github/workflows/release.yml — Docker Hub image renamed to $DOCKERHUB_USERNAME/lobstr.
• Makefile — docker-build/docker-run build and run lobstr:local.

Notes

• The Docker Hub rename takes effect on the next dev → main release; that release will push <user>/lobstr (a new repo) instead of <user>/lobstr-swa. Ensure the lobstr Docker Hub repo exists / the token can create it.
• No change to GitHub Pages deployment (it publishes the swa/ directory by path, independent of the image name).

Test plan

• CI docker job builds lobstr:ci, the container becomes healthy, and teardown succeeds.
• make docker-build produces lobstr:local and make docker-run serves at http://localhost:8080.