Add native Spindle workflows for pull requests, main pushes, version tags, and manual test runs. Tests run Go directly. Container publication runs only after the full Go/E2E suite and container smoke check pass.
Publish containers to Docker Hub and atcr.io/kenneth.nym.sh/tasker. Main pushes publish edge; version tags publish their SemVer version, with stable releases advancing latest independently in each registry. PR and manual runs never publish. The existing GitHub publishing workflow also gains ATCR support.
Setup is documented in .tangled/README.md, including required secrets (DOCKERHUB_USERNAME, DOCKERHUB_TOKEN, and ATCR_APP_PASSWORD), optional image/handle overrides, runner requirements, and publication serialization. Spindle has no workflow publication lock; overlapping publishing runs must be serialized externally.
Validation: full Go/E2E suite passed; all 17 Python publishing tests passed; local Docker build and smoke check passed; workflow YAML and shell syntax checks passed. Live registry publication and a hosted Spindle run have not been verified.