【后端接口】挖矿采集：进度操作与黑铁产出

---挖矿：工具校验与进度拉起
function Mine.start(actor, veinId)
    local player = class(actor)
    if not player then return end
    if not checkitemw(actor, "鹤嘴锄", 1) then
        sendmsg(actor, 1, "需要装备鹤嘴锄才能挖矿")
        return false
    end
    local vein = Mine.veinOf(veinId)
    if not vein or vein.depleted then
        sendmsg(actor, 1, "该矿点已枯竭")
        return false
    end
    -- 拉起采集进度条：8 秒一次采挖
    showprogressbardlg(actor, 8, "正在挖矿...")
    Mine.binding(actor, veinId)
    return true
end

---采挖结算：品质分层产出
setontimerex(87, 1)
function Mine.harvest(actor)
    local player = class(actor)
    if not player then return end
    local veinId = Mine.boundVein(actor)
    if not veinId then return end
    local vein = Mine.veinOf(veinId)
    -- 品质掷骰：纯度 10/15/20 三档
    local r = math.random(1, 100)
    local purity = (r <= 60 and 10) or (r <= 90 and 15) or 20
    giveitem(actor, "黑铁矿石", 1)
    Mine.tagPurity(actor, purity)
    vein.count = vein.count - 1
    if vein.count <= 0 then
        vein.depleted = true
        vein.rebornAt = os.time() + 3600   -- 1 小时后重生
        sendmsg(actor, 1, "矿点已挖空，1 小时后刷新")
    end
end