【引擎触发】groupkillmon：组队击杀的共享结算

---groupkillmon: 组队杀怪 同地图成员每人触发一次
function groupkillmon(actor, monName)
    local player = getplayerbyname(actor)   -- 字符串转玩家对象
    if not player then return end
    -- 队伍人数的经验加成：四人队每人 120%
    local size = Group.sizeOf(player)
    local bonus = 100 + math.min(size - 1, 5) * 5
    local base = MON_EXP[monName] or 100
    local exp = math.floor(base * 1.0 * bonus / 100)
    humanhp(player, "+", 0)
    sendmsg(player, 1, "组队经验 +" .. exp .. "（队伍加成 " ..
        bonus .. "%）")
    Group.addExp(player, exp)
end

---组队击杀推进师徒历练与周任务
function Group.onKill(actor, monName)
    local player = getplayerbyname(actor)
    if not player then return end
    -- 师徒历练：师父在队则历练 +1
    local master = getplayvar(player, 2, "MasterName")
    if master and master ~= "" and Group.hasMember(player, master) then
        Mentor.taskDone(player, master)
    end
    -- 行会周任务的击杀进度
    local gid = getplayvar(player, 2, "GuildId")
    if gid and gid ~= "" then
        GuildWeekly.progress(gid, "kill", 1)
    end
end