feat: 收口知识库分享链路

- 新增 shareKey 单参数 URL 分享页与失效页

- 新增知识库分享后端鉴权、审计与迁移脚本

- 在访问令牌中增加知识库分享授权入口

easyflow-ui-admin/app/src/api/knowledge-share.ts

@@ -0,0 +1,82 @@
+import { api } from '#/api/request';
+
+const EXPIRED_ERROR_CODES = new Set([4601, 4602]);
+const SHARE_ERROR_REASON: Record<number, string> = {
+  4601: 'expired',
+  4602: 'invalid',
+};
+const APP_BASE_PATH = (import.meta.env.BASE_URL || '/').replace(/\/$/, '');
+
+function getShareParams() {
+  const params = new URLSearchParams(window.location.search);
+  const shareKey = params.get('shareKey') || '';
+  return { shareKey };
+}
+
+function appendShareQuery(url: string, extraParams?: Record<string, any>) {
+  const base =
+    typeof window === 'undefined' ? 'http://localhost' : window.location.origin;
+  const target = new URL(url, base);
+  const { shareKey } = getShareParams();
+  if (shareKey) {
+    target.searchParams.set('shareKey', shareKey);
+  }
+  Object.entries(extraParams || {}).forEach(([key, value]) => {
+    if (value === undefined || value === null || value === '') {
+      return;
+    }
+    target.searchParams.set(key, String(value));
+  });
+  return `${target.pathname}${target.search}`;
+}
+
+function redirectIfExpired(response: any) {
+  const errorCode = Number(response?.errorCode);
+  if (!response || !EXPIRED_ERROR_CODES.has(errorCode)) {
+    return response;
+  }
+  const reason = SHARE_ERROR_REASON[errorCode] || 'expired';
+  window.location.assign(
+    `${APP_BASE_PATH}/share/knowledge/expired?reason=${reason}`,
+  );
+  return response;
+}
+
+export const knowledgeShareApi = {
+  get(url: string, config?: Record<string, any>) {
+    return api
+      .get(appendShareQuery(url, config?.params), {
+        ...config,
+        params: undefined,
+      })
+      .then(redirectIfExpired);
+  },
+  post(url: string, data?: any, config?: Record<string, any>) {
+    return api
+      .post(appendShareQuery(url), data, config)
+      .then(redirectIfExpired);
+  },
+  postFile(url: string, data?: any, config?: Record<string, any>) {
+    return api
+      .postFile(appendShareQuery(url), data, config)
+      .then(redirectIfExpired);
+  },
+  upload(url: string, data?: any, config?: Record<string, any>) {
+    return api
+      .upload(appendShareQuery(url), data, config)
+      .then(redirectIfExpired);
+  },
+  download(url: string, config?: Record<string, any>) {
+    return api.download(appendShareQuery(url, config?.params), {
+      ...config,
+      params: undefined,
+    });
+  },
+};
+
+export function buildKnowledgeShareUrl(
+  url: string,
+  extraParams?: Record<string, any>,
+) {
+  return appendShareQuery(url, extraParams);
+}