/**
 * Per-cwd PI runtime registry.
 *
 * Holds the cwd-keyed `HooksRuntime` cache, the most-recent `ExtensionContext`
 * per cwd (so HostAdapter UI calls can reach `ctx.ui` outside the event
 * handler scope), and the LRU bookkeeping that bounds both maps.
 *
 * Exposes:
 * - `getRuntimeFor(cwd)`   — lazy-construct + memoise the runtime for a cwd
 * - `rememberContext(cwd, ctx)` — record the freshest ctx for that cwd
 * - `getLatestContext(cwd)` — peek the freshest ctx (used by user-bash plumbing)
 * - `touchLruEntry` / `evictLruEntries` — pure helpers, exported for tests (P2-6)
 *
 * Extracted from `adapter.ts` as part of the P0/P1 refactor; behaviour and
 * eviction policy are unchanged.
 */
import type { ExtensionAPI, ExtensionContext } from "@earendil-works/pi-coding-agent";
import { type HooksRuntime } from "../core/runtime.js";
export interface RuntimeRegistry {
    getRuntimeFor(cwd: string): HooksRuntime;
    rememberContext(cwd: string, ctx: ExtensionContext): void;
    getLatestContext(cwd: string): ExtensionContext | undefined;
}
export declare function createRuntimeRegistry(pi: ExtensionAPI): RuntimeRegistry;
/**
 * Promote `cwd` to most-recent. If the key exists, it is re-inserted so that
 * Map iteration order places it last (the freshest entry). Used by both the
 * production runtime (via `touchCwd`) and unit tests (via `__testing__`),
 * so the LRU eviction policy has a single source of truth (P2-6).
 */
export declare function touchLruEntry<T>(map: Map<string, T>, cwd: string): void;
/**
 * Drop oldest entries from `map` (and `companion`, if provided) until at
 * most `maxEntries` remain. Returns the keys that were evicted. Shared
 * between the production `evictIfNeeded` and the test surface (P2-6).
 */
export declare function evictLruEntries<T>(map: Map<string, T>, maxEntries: number, companion?: Map<string, unknown>): string[];