/**
 * [WHO]: insights extension default export (/insights command)
 * [FROM]: Depends on node:path, node:fs/promises, core/extensions-host/types, core/session/session-manager, ./types, ./stats, ./insights-engine, ./html-report, ./prompts, ./session-scanner
 * [TO]: Auto-loaded by builtin-extensions.ts as a default extension
 * [HERE]: extensions/builtin/insights/index.ts - /insights command entry; usage-report pipeline
 *
 * /insights command — generate a usage report analyzing Catui sessions.
 *
 * 1:1 port of Claude Code src/commands/insights.ts generateUsageReport() pipeline.
 *
 * Pipeline:
 * 1. scanAllSessions() — filesystem metadata only (no JSONL parsing)
 * 2. Load SessionMeta — cache-first, parse uncached
 * 3. Deduplicate session branches
 * 4. Filter substantive sessions (≥2 user messages, ≥1 minute)
 * 5. Facet extraction — cache-first, LLM for uncached (max 50)
 * 6. Filter minimal sessions (warmup_minimal only)
 * 7. aggregateData() — cross-session statistics
 * 8. generateParallelInsights() — 7+ parallel LLM calls
 * 9. generateHtmlReport() — HTML report with charts
 * 10. Save report + terminal summary
 */
import type { ExtensionAPI } from "../../../core/extensions-host/types.js";
export type InsightsProgressCallback = (phase: string, detail?: string) => void;
export default function insightsExtension(api: ExtensionAPI): Promise<void>;