Add ExternalSecret for ISSUE_CORE_API_KEY on Railiance

Sync the shared issue-core ingestion key from OpenBao into
actcore-runtime-secret via External Secrets, with an interim coulombcore
ClusterSecretStore bootstrap script and deploy docs. Removes manual key
injection from bootstrap-secrets.sh.

scripts/openbao-eso-token-apply.sh

@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+# Mint a read-limited OpenBao token on coulombcore (bao.coulomb.social) and store
+# it on railiance01 for ClusterSecretStore openbao-activity-core / ExternalSecret
+# actcore-issue-core-runtime.
+set -euo pipefail
+
+POLICY_NAME="${OPENBAO_ACTIVITY_CORE_POLICY:-workload-kv-read-issue-core-runtime}"
+POLICY_FILE="${OPENBAO_ACTIVITY_CORE_POLICY_FILE:-$HOME/railiance-platform/openbao/policies/workload-kv-read-issue-core-runtime.hcl}"
+BAO_ADDR="${BAO_ADDR:-https://bao.coulomb.social}"
+RAILIANCE01_KUBECONFIG="${RAILIANCE01_KUBECONFIG:-$HOME/.kube/config-hosteurope}"
+SECRET_NAME="${OPENBAO_ACTIVITY_CORE_ESO_SECRET:-openbao-activity-core-eso-token}"
+SECRET_NS="${OPENBAO_ACTIVITY_CORE_ESO_NAMESPACE:-external-secrets}"
+
+if ! command -v bao >/dev/null 2>&1; then
+  echo "ERROR: bao CLI not found" >&2
+  exit 1
+fi
+
+if [[ ! -f "$POLICY_FILE" ]]; then
+  echo "ERROR: policy file missing: $POLICY_FILE" >&2
+  exit 1
+fi
+
+echo "OpenBao addr: $BAO_ADDR"
+echo "Policy: $POLICY_NAME"
+
+if [[ -n "${BAO_TOKEN:-}" ]]; then
+  :
+elif [[ -n "${OPENBAO_TOKEN_FILE:-}" && -f "${OPENBAO_TOKEN_FILE}" ]]; then
+  BAO_TOKEN="$(head -n 1 "${OPENBAO_TOKEN_FILE}")"
+else
+  read -r -s -p "OpenBao operator token (coulombcore / bao.coulomb.social): " BAO_TOKEN
+  echo >&2
+fi
+
+if [[ -z "${BAO_TOKEN:-}" ]]; then
+  echo "ERROR: empty OpenBao token" >&2
+  exit 1
+fi
+
+export BAO_ADDR BAO_TOKEN
+
+health="$(curl -fsS "$BAO_ADDR/v1/sys/health")"
+if echo "$health" | grep -q '"sealed":true'; then
+  echo "ERROR: OpenBao at $BAO_ADDR reports sealed" >&2
+  exit 1
+fi
+
+bao policy write "$POLICY_NAME" "$POLICY_FILE"
+token_json="$(bao token create -policy="$POLICY_NAME" -display-name="eso-activity-core-issue-sink" -period=720h -format=json)"
+token="$(python3 -c "import json,sys; print(json.load(sys.stdin)['auth']['client_token'])" <<<"$token_json")"
+
+KUBECONFIG="$RAILIANCE01_KUBECONFIG" kubectl create namespace "$SECRET_NS" --dry-run=client -o yaml | KUBECONFIG="$RAILIANCE01_KUBECONFIG" kubectl apply -f -
+KUBECONFIG="$RAILIANCE01_KUBECONFIG" kubectl create secret generic "$SECRET_NAME" \
+  --namespace "$SECRET_NS" \
+  --from-literal=token="$token" \
+  --dry-run=client -o yaml | KUBECONFIG="$RAILIANCE01_KUBECONFIG" kubectl apply -f -
+
+unset BAO_TOKEN token token_json
+echo "ok: applied $SECRET_NS/$SECRET_NAME on railiance01 (token not printed)"