add sign in page

front/src/pages/overview-state.test.ts

@@ -0,0 +1,18 @@
+import assert from 'node:assert/strict';
+import { test } from 'node:test';
+
+import { getOverviewLoadErrorMessage } from './overview-state';
+
+test('post-login failures are presented as overview initialization issues', () => {
+  assert.equal(
+    getOverviewLoadErrorMessage(true),
+    '登录已成功，但总览数据加载失败，请稍后重试。'
+  );
+});
+
+test('generic overview failures stay generic when not coming right after login', () => {
+  assert.equal(
+    getOverviewLoadErrorMessage(false),
+    '总览数据加载失败，请稍后重试。'
+  );
+});