static inline uint32_t sll_cap_for_class(int class_idx, uint32_t mag_cap) {
    // Phase12+: 旧 g_sll_cap_override は削除済み。ここでは通常capのみを使用する。
    uint32_t cap = mag_cap;
    if (class_idx <= 3) {
        uint32_t mult = (g_sll_multiplier > 0 ? (uint32_t)g_sll_multiplier : 1u);
        uint64_t want = (uint64_t)cap * (uint64_t)mult;
        if (want > (uint64_t)TINY_TLS_MAG_CAP) cap = TINY_TLS_MAG_CAP; else cap = (uint32_t)want;
    } else if (class_idx >= 4) {
        cap = (mag_cap > 1u ? (mag_cap / 2u) : 1u);
    }
    return cap;
}