/**
 * Turn-boundary context cleanup.
 *
 * Background. The conversation history sent to the model grows as:
 *   [user, assistant(tool_calls), tool, assistant(tool_calls), tool, …,
 *    assistant(final text), user, assistant(tool_calls), tool, …]
 *
 * Once a turn is *complete* (assistant returned text with no tool_calls),
 * the in-progress scaffolding from that turn — the assistant messages
 * carrying tool_calls and the tool-result messages — is no longer
 * actionable. But it still LOOKS actionable to a weaker model: it sees
 * "tool_calls" entries and treats them as pending TODOs, which is why
 * owl-alpha kept re-writing the same poem on every new user turn:
 *
 *     turn 1 user: "write a poem"
 *     ... model writes poem ...
 *     turn 2 user: "find a github repo for X"
 *     model: "I'll handle BOTH requests" (because it still sees the
 *            poem's tool_calls scaffolding as if it hadn't run)
 *     turn 3 user: "research further"
 *     model: "I'll handle all THREE requests"  ← infinite re-execution
 *
 * Fix. Before each new turn, walk back through history. For every
 * COMPLETED turn (any turn before the latest user message), collapse the
 * [user, ...intermediate scaffolding..., final assistant text] sequence
 * into [user, "final assistant text + [Completed: used X, Y]"]. The model
 * sees a clean conversational record of what already happened, with no
 * dangling tool_calls signals to misinterpret.
 *
 * The currently-active turn (everything from the latest user message
 * forward) is left untouched — its tool_calls and tool-result messages
 * are still in-flight and the API protocol requires them paired.
 */
import type { Message } from './types.js';
/**
 * Collapse all completed turns in a message list. Returns a new array;
 * input is not mutated.
 *
 * A completed turn is any turn ENDING before the latest user message.
 * The latest user message and everything after it is the "active turn"
 * and is passed through unchanged.
 */
export declare function collapseCompletedTurns(messages: Message[]): Message[];