/**
 * Fast loop analysis — the default strategy of loop.detect().
 * Pipeline: beat tracking → onset detection → precise onset-pair search,
 * falling back (within this strategy, by design) to bar-aligned search and
 * finally to a documented half-buffer heuristic whose confidence is measured,
 * not fabricated.
 *
 * @param {AudioBuffer|Object} audioBuffer - AudioBuffer or shim with
 *   { getChannelData, sampleRate, duration }
 * @returns {Promise<Object>} { loopStart, loopEnd, confidence, bpm, ... }
 */
export function fastLoopAnalysis(audioBuffer: AudioBuffer | any): Promise<any>;