Fix sourced vault bootstrap exits

scripts/load-vault-env.sh

@@ -2,20 +2,20 @@
 set -eu
 
 if [ "${VAULT_ENABLED:-auto}" = "false" ] || [ "${VAULT_ENABLED:-auto}" = "0" ]; then
-  exit 0
+  return 0 2>/dev/null || exit 0
 fi
 
 if [ -z "${VAULT_ADDR:-}" ] || [ -z "${VAULT_TOKEN:-}" ]; then
   if [ "${VAULT_ENABLED:-auto}" = "true" ] || [ "${VAULT_ENABLED:-auto}" = "1" ]; then
     echo "VAULT_ENABLED=true but VAULT_ADDR/VAULT_TOKEN are not set" >&2
-    exit 1
+    return 1 2>/dev/null || exit 1
   fi
-  exit 0
+  return 0 2>/dev/null || exit 0
 fi
 
 if ! command -v curl >/dev/null 2>&1 || ! command -v jq >/dev/null 2>&1; then
   echo "Vault bootstrap requires curl and jq." >&2
-  exit 1
+  return 1 2>/dev/null || exit 1
 fi
 
 kv_mount="${VAULT_KV_MOUNT:-secret}"