from typing import Optional


def align(left_segments: list[dict], right_segments: list[dict]) -> list[dict]:
    merged = []

    for seg in left_segments:
        merged.append({
            "start": seg["start"],
            "end": seg["end"],
            "speaker": "callee",
            "text": seg["text"].strip(),
        })

    for seg in right_segments:
        merged.append({
            "start": seg["start"],
            "end": seg["end"],
            "speaker": "caller",
            "text": seg["text"].strip(),
        })

    merged.sort(key=lambda s: s["start"])
    return merged