feat(agent): 检索工具、模型接入与结构化回复

Agent 按组织与知识源范围调用检索工具，密钥加密保存，回复含来源与转人工意图。

frontend/src/utils/aiDisclaimer.ts

@@ -0,0 +1,41 @@
+/*
+Copyright 2024-2026 ChatterMate
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+/**
+ * The footer line disclosing that replies are AI-generated.
+ *
+ * Copy and visibility rule live here, not in each template, so the live widget,
+ * the dashboard preview and the settings description cannot drift apart.
+ */
+export const AI_DISCLAIMER_TEXT = 'AI 也可能出错，重要信息请核实。'
+
+/**
+ * Whether the disclosure should be rendered.
+ *
+ * Two deliberate choices:
+ *
+ * - `!== false` rather than `=== true`. A widget served before this setting
+ *   existed sends no value at all, and missing configuration must fail towards
+ *   disclosing rather than towards hiding.
+ * - Hidden once a human agent takes the conversation over. From that point the
+ *   replies are written by a person, so the line would simply be untrue.
+ */
+export function shouldShowAiDisclaimer(
+  enabled: boolean | undefined | null,
+  handedOverToHuman = false,
+): boolean {
+  return enabled !== false && !handedOverToHuman
+}