Add railiance01 deployment artifacts and fix container image build

Introduce Dockerfile, entrypoint, and k8s/railiance manifests for the
ArgoCD GitOps pilot (ISSUE-WP-0003). Rename the Gitea PyPI build arg to
GITEA_PYPI_INDEX_URL so pip still resolves dependencies from PyPI.

k8s/railiance/externalsecret.yaml

@@ -0,0 +1,37 @@
+# Runtime secrets for issue-core, materialized from OpenBao by External Secrets
+# Operator (cluster default per railiance-platform docs/argocd-gitops.md).
+#
+# DEPENDENCY: External Secrets Operator is not yet installed on railiance01 and
+# the OpenBao path below must be provisioned by railiance-platform. Until then
+# this resource will not reconcile and the Deployment stays Pending the Secret.
+#
+# OpenBao path: platform/workloads/issue-core/issue-core/issue-core-runtime
+#   properties: ISSUE_CORE_API_KEY, GITEA_BACKEND_TOKEN
+apiVersion: external-secrets.io/v1beta1
+kind: ExternalSecret
+metadata:
+  name: issue-core-runtime
+  namespace: issue-core
+  labels:
+    app.kubernetes.io/name: issue-core
+    app.kubernetes.io/part-of: railiance-gitops
+  annotations:
+    argocd.argoproj.io/sync-wave: "0"  # before the Deployment (wave 1)
+spec:
+  refreshInterval: 1h
+  secretStoreRef:
+    # Provisioned by railiance-platform during ESO install; name TBC on bootstrap.
+    name: openbao
+    kind: ClusterSecretStore
+  target:
+    name: issue-core-runtime
+    creationPolicy: Owner
+  data:
+    - secretKey: ISSUE_CORE_API_KEY
+      remoteRef:
+        key: platform/workloads/issue-core/issue-core/issue-core-runtime
+        property: ISSUE_CORE_API_KEY
+    - secretKey: GITEA_BACKEND_TOKEN
+      remoteRef:
+        key: platform/workloads/issue-core/issue-core/issue-core-runtime
+        property: GITEA_BACKEND_TOKEN