add backend readiness contract for publish prechecks
guard publish flow with explicit validation and version-aware checks
make publish behavior more predictable for clients and safer against stale state
add backend readiness contract for publish prechecks
add pricing diagnostics to explain publish-blocking conditions
make publish decisions more explicit and easier to debug for clients
add backend endpoint for publish readiness checks
enforce publish gate contract before version publication
make publish preconditions explicit and consistent for clients