【运维发布】灰度开关平台：功能开关的集中管理

---功能开关：配置驱动的放量
local FLAGS = {}
-- FLAGS["rune_system"] = { on = true, rate = 5, allow = {"血饮狂刀"} }

function Flag.on(key, actor)
    local f = FLAGS[key]
    if not f or not f.on then return false end
    -- 白名单优先
    if actor and f.allow and f.allow[actor:GetName()] then
        return true
    end
    -- 百分比放量：按用户 ID 稳定散列
    if actor then
        local h = Flag.hash(actor:GetUserId())
        return h % 100 < f.rate
    end
    return f.rate >= 100
end

---业务侧的开关判断
function Entry.openRune(actor)
    if not Flag.on("rune_system", actor) then
        return false
    end
    return true
end

---开关的热更新：每 10 秒拉取配置
setontimerex(77, 10)
function Flag.sync()
    local cfg = FlagCenter.pull()
    if cfg and cfg.version ~= FLAGS.version then
        FLAGS = cfg
        Ops.log("开关配置已更新至 v" .. cfg.version)
    end
end

---一键回退：全量到零
function Flag.rollBack(key)
    FlagCenter.set(key, { on = false, rate = 0 })
end