fix(auth): require jumpToken for access, remove temporary bypass

Previously: no jumpToken → direct access allowed (临时放行)
Now: no jumpToken → show "请从业务系统跳转访问" unauthorized page

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/auth/AuthProvider.tsx

@@ -65,8 +65,7 @@ export default function AuthProvider({ children }: { children: ReactNode }) {
     const jumpToken = params.get('jumpToken');
 
     if (!jumpToken) {
-      // 临时：无 token 时直接放行
-      setState({ isLoading: false, isAuthenticated: true, user: null, error: null });
+      setState({ isLoading: false, isAuthenticated: false, user: null, error: '请从业务系统跳转访问' });
       return;
     }