feat: 接入知识库聊天入口与前端路由

在聊天页工具栏接入「保存到知识库」按钮，并补回 /page/workspace/knowledge 列表/详情/图谱路由（此前被回退丢失）。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend-web/src/pages/ChatPage.tsx

@@ -15,6 +15,7 @@ import {
   useThreadChat,
 } from "@/components/workspace/chats";
 import { ExportTrigger } from "@/components/workspace/export-trigger";
+import { KnowledgeSaveTrigger } from "@/components/workspace/knowledge-save-trigger";
 import { InputBox } from "@/components/workspace/input-box";
 import {
   MessageList,
@@ -409,6 +410,7 @@ export default function ChatPage() {
                 messages={thread.messages}
               />
               <ExportTrigger threadId={threadId} />
+              <KnowledgeSaveTrigger threadId={threadId} />
               <ArtifactTrigger />
             </div>
           </header>

frontend-web/src/pages/WorkspaceRoutes.tsx

@@ -24,6 +24,8 @@ import AdminScheduledTasksPage from './AdminScheduledTasksPage';
 import AdminSkillsPage from './AdminSkillsPage';
 import ScheduledTaskRunDetailPage from './ScheduledTaskRunDetailPage';
 import ScheduledTasksPage from './ScheduledTasksPage';
+import KnowledgeBasePage from './KnowledgeBasePage';
+import KnowledgeGraphPage from './KnowledgeGraphPage';
 import LlmMetricsPage from './LlmMetricsPage';
 import CheckpointMigrationPage from './CheckpointMigrationPage';
 import MemoryPage from './MemoryPage';
@@ -335,6 +337,30 @@ export default function WorkspaceRoutes({
             </WorkspaceLayout>
           }
         />
+        <Route
+          path="knowledge"
+          element={
+            <WorkspaceLayout {...layoutProps}>
+              <KnowledgeBasePage />
+            </WorkspaceLayout>
+          }
+        />
+        <Route
+          path="knowledge/graph"
+          element={
+            <WorkspaceLayout {...layoutProps}>
+              <KnowledgeGraphPage />
+            </WorkspaceLayout>
+          }
+        />
+        <Route
+          path="knowledge/:noteId"
+          element={
+            <WorkspaceLayout {...layoutProps}>
+              <KnowledgeBasePage />
+            </WorkspaceLayout>
+          }
+        />
         <Route
           path="scheduled"
           element={<Navigate to="/page/workspace/scheduled/tasks" replace />}