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 (where worker code actually lives)
- Remove unnecessary packages from apk add
- Change workdir to /app (no /workflows subdirectory)
- Fix go run path to ./cmd/worker
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.