def align_records(cobol_records: list[dict], java_records: list[dict],
                 key_field: str = "CUST-ID") -> list[tuple]:
    """对齐COBOL和Java记录
    
    Args:
        cobol_records: COBOL输出记录列表
        java_records: Java输出记录列表
        key_field: 用于对齐的关键字段名（默认为"CUST-ID"）
    
    Returns:
        对齐结果列表，每个元素为 (cobol_record, java_record, status)
        status: "MATCHED", "MISSING_IN_SPARK", "EXTRA_IN_SPARK"
    """
    if not cobol_records and not java_records:
        return []
    
    # 智能关键字段推断：如果默认key_field不存在，尝试推断
    effective_key = key_field
    if cobol_records:
        sample_record = cobol_records[0]
        if effective_key not in sample_record:
            # 尝试常见的关键字段名
            common_keys = ["ID", "CUST-ID", "EMP-ID", "KEY", "CODE", "NO"]
            for k in common_keys:
                if k in sample_record:
                    effective_key = k
                    break
    
    def _by(records, kf):
        d = {}
        for r in records:
            key = str(r.get(kf, "__NONE__"))
            d.setdefault(key, []).append(r)
        return d
    
    c_by = _by(cobol_records, effective_key)
    j_by = _by(java_records, effective_key)
    pairs = []
    all_keys = set(c_by) | set(j_by)
    
    for k in sorted(all_keys):
        c_items = c_by.get(k, [])
        j_items = j_by.get(k, [])
        for i in range(max(len(c_items), len(j_items))):
            c = c_items[i] if i < len(c_items) else None
            j = j_items[i] if i < len(j_items) else None
            if c and j:
                pairs.append((c, j, "MATCHED"))
            elif c:
                pairs.append((c, None, "MISSING_IN_SPARK"))
            else:
                pairs.append((None, j, "EXTRA_IN_SPARK"))
    return pairs