// SPDX-License-Identifier: Apache-2.0
// Copyright (c) 2025 ReifyDB
//! RQL planning for CREATE FLOW. Analyses the source query, builds the operator graph, plans each operator
//! against the catalog, and produces the persisted flow definition the engine hands to `sub-flow` at runtime.
//! Dataflow shape - which operator depends on which - is settled here, not in the streaming runtime.