feat: 新增知识卡片页面及路由支持

- 添加知识卡片 API 接口与 Mock 数据
- 实现知识卡片列表展示与筛选功能
- 实现知识卡片详情抽屉
- 支持路由嵌套配置与菜单展开

frontend/src/api/knowledgeCards.ts

@@ -0,0 +1,38 @@
+import { get } from '@/utils/request'
+
+export type KnowledgeCardType = 'global' | 'product' | 'chat'
+export type KnowledgeCardAuditStatus = 'pending' | 'approved'
+
+export interface RelatedProduct {
+  id: number
+  name: string
+}
+
+export interface RelatedChat {
+  id: number
+  name: string
+}
+
+export interface KnowledgeCard {
+  id: number
+  title: string
+  content: string
+  type: KnowledgeCardType
+  auditStatus: KnowledgeCardAuditStatus
+  author: string
+  updatedAt: string
+  coverColor: string
+  tags: string[]
+  relatedProducts: RelatedProduct[]
+  relatedChats: RelatedChat[]
+}
+
+export interface GetKnowledgeCardsParams {
+  type?: KnowledgeCardType
+  auditStatus?: KnowledgeCardAuditStatus
+}
+
+/** 获取知识卡片列表 */
+export function getKnowledgeCards(params?: GetKnowledgeCardsParams) {
+  return get<KnowledgeCard[]>('/knowledge/cards', params as Record<string, string>)
+}