docs: add pre-release functional test design + screenshots

docs/screenshots/settings-mode-toggle.txt

@@ -0,0 +1,53 @@
+uid=2_0 RootWebArea "ZCLAW" url="http://localhost:1420/"
+  uid=5_0 complementary
+    uid=5_1 button "返回应用"
+    uid=5_2 navigation
+      uid=5_3 button "通用"
+      uid=5_4 button "用量统计"
+      uid=5_5 button "积分详情"
+      uid=5_6 button "模型与 API"
+      uid=5_7 button "MCP 服务"
+      uid=5_8 button "IM 频道"
+      uid=5_9 button "工作区"
+      uid=5_10 button "数据与隐私"
+      uid=5_11 button "安全存储"
+      uid=5_12 button "SaaS 平台"
+      uid=5_13 button "订阅与计费"
+      uid=5_14 StaticText "高级"
+      uid=5_15 button "技能管理"
+      uid=5_16 button "语义记忆"
+      uid=5_17 button "安全状态"
+      uid=5_18 button "审计日志"
+      uid=5_19 button "定时任务"
+      uid=5_20 button "心跳配置"
+      uid=5_21 button "提交反馈"
+      uid=5_22 button "关于"
+  uid=5_23 main
+    uid=5_24 heading "通用设置" level="1"
+    uid=5_25 heading "GATEWAY 连接" level="2"
+    uid=5_26 StaticText "状态"
+    uid=5_27 StaticText "已连接"
+    uid=5_28 StaticText "地址"
+    uid=5_29 StaticText "http://127.0.0.1:8080"
+    uid=5_30 StaticText "Token"
+    uid=5_31 textbox "可选：Gateway auth token" value="••••••••••••••••••••••••••••••••••••••••••••••••"
+    uid=5_32 StaticText "版本"
+    uid=5_33 StaticText "saas-relay"
+    uid=5_34 StaticText "当前模型"
+    uid=5_35 StaticText "GLM-4 Flash"
+    uid=5_36 button "断开连接"
+    uid=5_37 heading "外观与行为" level="2"
+    uid=5_38 StaticText "主题模式"
+    uid=5_39 StaticText "选择浅色或深色模式。"
+    uid=5_40 button
+    uid=5_41 button
+    uid=5_42 StaticText "开机自启"
+    uid=5_43 StaticText "登录时自动启动 ZCLAW。"
+    uid=5_44 button
+    uid=5_45 StaticText "显示工具调用"
+    uid=5_46 StaticText "在对话消息中显示模型的工具调用详情块。"
+    uid=5_47 button
+    uid=5_48 StaticText "界面模式"
+    uid=5_49 StaticText "切换简洁界面或完整专业界面。"
+    uid=5_50 button "简洁模式 适合日常使用，只显示聊天窗口"
+    uid=5_51 button "专业模式 完整功能，包括侧边栏和工具面板" focusable focused