go.mod required go >= 1.25.4 but golang:1.25-alpine doesn't exist yet.
Downgrade to go 1.23 which is available in Alpine images and sufficient
for the codebase. Update both deployment and job images to golang:1.23-alpine.
- Clone from poimen-workflows.git (correct repo)
- Remove unnecessary gcc and musl-dev (not needed for running Go binaries)
- Fix cd path from /app/workflows to /app
Implements real activity-calling logic in OrchestratorWorkflow and
TaskUnitWorkflow (previously stubs), adds GitDiffActivity, and expands
PlanningActivity's I/O to carry repo path and prior task results.
Adds k8s/ deployment manifests (worker Deployment, orchestrator Job,
Kustomize base) for the poimen-workflows Temporal worker, using a
dedicated Kubernetes namespace `poimen` and Temporal namespace
`poimen-harness` rather than sharing the Temporal server's own
`temporal`/`production` namespaces.