支持可配置的会话自动分配策略

- 租户可设置负载最低或轮询，以及每位坐席最大进行中会话数
- 自动分配按策略过滤在线一线客服，满并发则保持排队
- 系统设置「客服分配规则」页可保存上述配置

web/src/pages/agent/Settings.tsx

@@ -55,7 +55,7 @@ const tabItems: { key: string; label: string; desc: string; icon: ReactNode }[]
   { key: 'basic', label: '基本设置', desc: '租户展示名称、默认昵称与时区', icon: <SettingOutlined /> },
   { key: 'channels', label: '渠道管理', desc: '配置客户服务接入渠道与嵌入代码', icon: <ApiOutlined /> },
   { key: 'staff', label: '坐席账号', desc: '管理客服/主管账号与坐席配额', icon: <UserSwitchOutlined /> },
-  { key: 'assignment', label: '客服分配规则', desc: '会话自动分配策略说明', icon: <TeamOutlined /> },
+  { key: 'assignment', label: '客服分配规则', desc: '自动分配策略与并发上限', icon: <TeamOutlined /> },
   { key: 'autoreply', label: '自动回复', desc: '欢迎语与离线留言提示', icon: <MessageOutlined /> },
   { key: 'worktime', label: '工作时间', desc: '在线服务时段与非工作时间提示', icon: <ClockCircleOutlined /> },
   { key: 'notify', label: '通知设置', desc: '新会话、留言与日报偏好', icon: <BellOutlined /> },
@@ -71,6 +71,7 @@ const Settings = () => {
   const [autoReplyForm] = Form.useForm()
   const [workForm] = Form.useForm()
   const [notifyForm] = Form.useForm()
+  const [assignForm] = Form.useForm()
   const [staffForm] = Form.useForm()
   const [channels, setChannels] = useState<Channel[]>([])
   const [settings, setSettings] = useState<TenantSettings | null>(null)
@@ -142,6 +143,10 @@ const Settings = () => {
         notify_offline_leave: data.notify_offline_leave,
         notify_daily_report: data.notify_daily_report,
       })
+      assignForm.setFieldsValue({
+        assign_strategy: data.assign_strategy || 'least_load',
+        max_active_per_agent: data.max_active_per_agent ?? 0,
+      })
     } catch (e) {
       message.error(e instanceof Error ? e.message : '加载设置失败')
     } finally {
@@ -151,7 +156,7 @@ const Settings = () => {
 
   useEffect(() => {
     if (activeTab === 'channels') loadChannels()
-    if (['basic', 'autoreply', 'worktime', 'notify'].includes(activeTab)) loadSettings()
+    if (['basic', 'autoreply', 'worktime', 'notify', 'assignment'].includes(activeTab)) loadSettings()
     if (activeTab === 'staff' && canViewStaff) loadStaff()
   }, [activeTab])
 
@@ -504,29 +509,89 @@ const Settings = () => {
             )}
 
             {activeTab === 'assignment' && (
-              <div className="space-y-3">
-                <div className="bg-white rounded-xl border border-[#dbeafe] shadow-sm p-5">
-                  <div className="flex items-start gap-3">
-                    <div className="w-9 h-9 rounded-lg bg-[#eff6ff] text-[#2563eb] flex items-center justify-center shrink-0">
-                      <TeamOutlined />
-                    </div>
-                    <div>
-                      <div className="text-sm font-medium text-neutral-800">当前生效：负载最低优先 + 工作时间</div>
-                      <div className="text-xs text-neutral-500 mt-1.5 leading-relaxed">
-                        工作时间内，新会话自动分配给进行中会话最少的在线客服；非工作时间或无客服在线时，访客可提交离线留言。
+              <div className="space-y-4">
+                {loadingSettings ? (
+                  <div className="py-16 text-center"><Spin /></div>
+                ) : (
+                  <>
+                    <div className="bg-white rounded-xl border border-[#dbeafe] shadow-sm p-5">
+                      <div className="flex items-start gap-3">
+                        <div className="w-9 h-9 rounded-lg bg-[#eff6ff] text-[#2563eb] flex items-center justify-center shrink-0">
+                          <TeamOutlined />
+                        </div>
+                        <div className="min-w-0">
+                          <div className="text-sm font-medium text-neutral-800">自动分配规则</div>
+                          <div className="text-xs text-neutral-500 mt-1.5 leading-relaxed">
+                            工作时间内，访客进线会按下列策略分配给<strong className="font-medium text-neutral-700">在线一线客服</strong>；
+                            非工作时间或无可接坐席时进入排队/留言。人工领取与转接不受此策略限制。
+                          </div>
+                        </div>
                       </div>
                     </div>
-                  </div>
-                </div>
-                <div className="bg-white rounded-xl border border-neutral-200 p-5 opacity-70">
-                  <div className="flex items-center justify-between">
-                    <div>
-                      <div className="text-sm font-medium text-neutral-800">轮询分配</div>
-                      <div className="text-xs text-neutral-400 mt-1">后续版本可切换策略</div>
+
+                    <div className="bg-white rounded-xl border border-neutral-200 shadow-sm p-5">
+                      <Form
+                        form={assignForm}
+                        layout="vertical"
+                        disabled={!isAdmin}
+                        onFinish={async (values: {
+                          assign_strategy: 'least_load' | 'round_robin'
+                          max_active_per_agent: number
+                        }) => {
+                          await savePartial({
+                            assign_strategy: values.assign_strategy,
+                            max_active_per_agent: Number(values.max_active_per_agent) || 0,
+                          }, '分配规则已保存')
+                        }}
+                      >
+                        <Form.Item
+                          name="assign_strategy"
+                          label="分配策略"
+                          rules={[{ required: true, message: '请选择策略' }]}
+                          extra="负载最低：优先进行中会话更少的坐席；轮询：在可接坐席中依次分配，更均匀。"
+                        >
+                          <Select
+                            options={[
+                              { value: 'least_load', label: '负载最低（推荐）' },
+                              { value: 'round_robin', label: '轮询分配' },
+                            ]}
+                          />
+                        </Form.Item>
+                        <Form.Item
+                          name="max_active_per_agent"
+                          label="每位坐席最大进行中会话数"
+                          rules={[
+                            { required: true, message: '请填写上限' },
+                            {
+                              validator: async (_, v) => {
+                                const n = Number(v)
+                                if (!Number.isFinite(n) || n < 0 || n > 200) {
+                                  throw new Error('请填写 0–200 的整数，0 表示不限制')
+                                }
+                              },
+                            },
+                          ]}
+                          extra="达到上限的坐席不再自动分入新会话；全部坐席已满时会话保持排队。0 = 不限制。"
+                        >
+                          <Input type="number" min={0} max={200} placeholder="0 表示不限制" />
+                        </Form.Item>
+                        {isAdmin ? (
+                          <Button type="primary" htmlType="submit" loading={saving}>
+                            保存分配规则
+                          </Button>
+                        ) : (
+                          <p className="text-xs text-neutral-400 m-0">仅租户管理员可修改分配规则</p>
+                        )}
+                      </Form>
                     </div>
-                    <Switch disabled />
-                  </div>
-                </div>
+
+                    <div className="bg-neutral-50 rounded-xl border border-neutral-200 p-4 text-xs text-neutral-500 leading-relaxed space-y-1">
+                      <div className="font-medium text-neutral-700 mb-1">说明</div>
+                      <p className="m-0">· 候选范围：角色为客服、状态为「在线」的账号（忙碌/离线不参与自动分配）。</p>
+                      <p className="m-0">· 技能组 / 渠道专属坐席将在后续版本支持。</p>
+                    </div>
+                  </>
+                )}
               </div>
             )}
 

web/src/services/api.ts

@@ -318,6 +318,8 @@ export const deleteStaff = (id: number) => del(`/staff/${id}`)
 
 // Tenant settings
 export type WorkHours = Record<string, string>
+export type AssignStrategy = 'least_load' | 'round_robin'
+
 export interface TenantSettings {
   tenant_id: number
   display_name: string
@@ -330,6 +332,10 @@ export interface TenantSettings {
   notify_new_session: boolean
   notify_offline_leave: boolean
   notify_daily_report: boolean
+  /** least_load 负载最低 | round_robin 轮询 */
+  assign_strategy?: AssignStrategy
+  /** 每位坐席最大进行中会话数，0=不限制 */
+  max_active_per_agent?: number
 }
 export const getTenantSettings = () => get<TenantSettings>('/settings')
 export const updateTenantSettings = (data: Partial<TenantSettings> & { work_hours?: WorkHours }) =>