/**
 * GUI-specific context management. GUI transcripts have an unusual shape: observations
 * are large and perishable (a viewport listing or screenshot is stale the moment the
 * screen changes), while actions are small and precious (the action log is what
 * prevents repeated side effects). So instead of summarizing (which burns the precise
 * action ledger), we structurally prune per the toolset's ContextPolicy:
 *   - keep the last `keepRecentObservations` gui tool results verbatim;
 *   - older gui tool results keep only their first line (the action/title line) plus
 *     a stale marker;
 *   - keep at most `keepImages` recent images; older ones become one-line placeholders.
 * Deliberately additive-free: we never inject summaries or reminders — measured in
 * gui-use, per-turn added guidance made the model over-cautious and cost more than
 * it saved.
 */
import type { AgentMessage } from "@earendil-works/pi-agent-core";
import { type ContextPolicy } from "../platform/types.ts";
export declare function pruneContext(messages: AgentMessage[], policy: ContextPolicy): AgentMessage[];