feat: 添加 Web 管理界面（Vue 3 SPA 单文件）+ /admin 挂载

tests/test_api.py

@@ -138,3 +138,16 @@ class TestDeleteEndpoint:
         results = search_resp.json()["results"]
         sources = [r["source_file"] for r in results]
         assert "delete-test.md" not in sources
+
+
+def test_admin_ui_served(client):
+    """管理界面可访问."""
+    response = client.get("/admin")
+    assert response.status_code == 200
+
+
+def test_health_skips_rate_limit(client):
+    """健康检查多次访问不触发速率限制."""
+    for _ in range(5):
+        resp = client.get("/api/v1/health")
+        assert resp.status_code == 200