【后端接口】装备修理：耐久消耗与修理费的经济账

---击杀结算：装备耐久的消耗
function Kill.durability(actor)
    local player = class(actor)
    if not player then return end
    -- 每杀 10 只掉 1 点持久，武器双倍
    local n = tonumber(getplayvar(actor, 2, "KillCount")) or 0
    setplayvar(actor, 2, "KillCount", n + 1, 0)
    if (n + 1) % 10 == 0 then
        setplayvar(actor, 2, "DurWeapon", -1, 0)
        sendmsg(actor, 1, "武器持久 -1，记得修理")
    end
end

---修理：普通修与特修双轨
function Repair.doFix(actor, mode)
    local player = class(actor)
    if not player then return false end
    -- 普通修：满持久但掉上限；特修：不掉上限
    local fee = mode == "special" and 20000 or 5000
    if not checkitemw(actor, "金币", fee) then
        sendmsg(actor, 1, "修理费不足，需 " .. fee .. " 金币")
        return false
    end
    takeitem(actor, "金币", fee, 0, mode == "special" and "特修" or "普修")
    if mode == "special" then
        setplayvar(actor, "HUMAN", "DurMaxOk", 1, 1)
        sendmsg(actor, 1, "特修完成，持久上限不变")
    else
        sendmsg(actor, 1, "修理完成，持久上限 -1")
    end
    return true
end