feat: 增强工作台趋势概览与聊天排行

- 支持用户活跃与智能体活跃趋势统计及自定义时间范围

- 增加用户活跃榜与智能体趋势数据结构及查询实现

- 同步补齐工作台页面展示与定向测试

easyflow-ui-admin/app/src/api/dashboard.ts

@@ -1,15 +1,18 @@
 import { requestClient } from '#/api/request';
 
-export type DashboardRange = '7d' | '30d' | 'today';
+export type DashboardRange = '7d' | '30d' | 'custom' | 'today';
 
 export interface DashboardOverviewQuery {
+  endDate?: string;
   range?: DashboardRange;
+  startDate?: string;
 }
 
 export interface DashboardSummary {
   activeUserTotal: number;
   activeAssistantTotal: number;
   botTotal: number;
+  chatActiveUserTotal: number;
   chatMessageTotal: number;
   chatSessionTotal: number;
   knowledgeBaseTotal: number;
@@ -30,10 +33,24 @@ export interface DashboardTrendItem {
   label: string;
 }
 
+export interface DashboardAssistantTrendPoint {
+  key: string;
+  label: string;
+  sessionTotal: number;
+}
+
+export interface DashboardAssistantTrendSeries {
+  assistantId?: number | string;
+  label: string;
+  points: DashboardAssistantTrendPoint[];
+  totalSessionCount: number;
+}
+
 export interface DashboardDistributionItem {
   activeUserTotal: number;
   assistantId?: number | string;
   avgMessagePerSession?: number;
+  avgSessionPerUser?: number;
   botTotal: number;
   key: string;
   knowledgeBaseTotal: number;
@@ -45,13 +62,23 @@ export interface DashboardDistributionItem {
   workflowTotal: number;
 }
 
+export interface DashboardUserRankItem {
+  assistantTotal: number;
+  label: string;
+  messageTotal: number;
+  sessionTotal: number;
+  userId?: number | string;
+}
+
 export interface DashboardOverviewResponse {
+  assistantTrends: DashboardAssistantTrendSeries[];
   chatStatus: DashboardChatStatus;
   distribution: DashboardDistributionItem[];
   query: DashboardOverviewQuery;
   summary: DashboardSummary;
   trends: DashboardTrendItem[];
   updatedAt: string;
+  userRanks: DashboardUserRankItem[];
 }
 
 export async function getDashboardOverview(params: DashboardOverviewQuery) {