fix(ui): Phase 7 C5 — 移除假按钮 + 真实托盘图标

用户报告设置页很多按钮无反应 + 关闭后托盘看不到图标。两处问题：\n\n1. ServerCard 占位按钮无回调：\n- server-card.slint：去掉了 toggled/edit-clicked/remove-clicked 三个回调以及 enabled 切换、Edit / Remove 按钮；变成纯展示卡（状态点 + name + url + 当前标记）\n- settings-page.slint：去掉硬编码的 Home / NAS 占位，改用 active-server-name / active-server-url / active-server-enabled 三个属性（MainWindow → AppConfig 实时填充）；空时显示 '（未配置服务器）' 空态提示\n- app.slint：MainWindow 加三个属性 + 转发给 SettingsPage\n- lib.rs：startup 阶段把活跃服务器信息塞进 UI；测试连接成功/失败时更新 enabled 状态\n\n2. 托盘图标看不见：\n- tray.rs：原本 hIcon 写 null，Win10+ 上 Shell_NotifyIconW(NIM_ADD, NULL hIcon) 实际渲染为空白或很弱的小方块。改用 LoadIconW(NULL, IDI_APPLICATION) 加载 Windows 自带的应用程序图标（无需嵌入 .ico 资源，主题感知）。show_toast / Drop 的 hIcon 维持 null（让 NIM_MODIFY/NIM_DELETE 不动原有图标）。AGENTS.md §53 标记真 .ico 资源为 V2 项。

ui/settings-page.slint

@@ -128,6 +128,16 @@ export component SettingsPage inherits Rectangle {
 
     callback toggle-persist(string, bool);
 
+    // Phase 7 C5: active server config (forwarded from MainWindow →
+    // AppConfig). Empty strings mean "未配置服务器". The page used to
+    // hardcode two placeholder rows ("Home" / "NAS") with Edit /
+    // Remove buttons that didn't do anything — that's what the user
+    // reported as "很多都没反应". V1 only has the single active
+    // server anyway, so a single card is honest about scope.
+    in property <string> active-server-name: "";
+    in property <string> active-server-url: "";
+    in property <bool> active-server-enabled: false;
+
     in property <color> divider-color: #3a3b40;
     in property <color> hint-color: #6a6a6a;
 
@@ -162,18 +172,35 @@ export component SettingsPage inherits Rectangle {
                 }
             }
 
-            ServerCard {
-                server-name: "Home";
-                server-url: "https://gotify.example.com";
-                enabled: true;
-                is-current: true;
-            }
-            ServerCard {
-                server-name: "NAS";
-                server-url: "http://192.168.50.103:50334";
-                enabled: true;
-                is-current: false;
-            }
+            // Phase 7 C5: 单卡显示活跃服务器。多 server 添加/编辑/
+            // 删除 UI 在 V2 实现（AGENTS.md §21），V1 只有一个活跃
+            // server。空字符串 → 空态。
+            if root.active-server-url != "":
+                ServerCard {
+                    server-name: root.active-server-name;
+                    server-url: root.active-server-url;
+                    enabled: root.active-server-enabled;
+                    is-current: true;
+                }
+
+            if root.active-server-url == "":
+                Rectangle {
+                    width: 100%;
+                    height: 56px;
+                    border-radius: 8px;
+                    background: #28292d;
+                    border-color: #3a3b40;
+                    border-width: 1px;
+                    Text {
+                        x: 16px;
+                        y: (parent.height - self.height) / 2;
+                        text: "（未配置服务器 — V1 暂不支持 UI 添加，请手动编辑 %APPDATA%\\WindowsGotify\\config.json）";
+                        color: #6a6a6a;
+                        font-size: 12px;
+                        wrap: word-wrap;
+                        width: parent.width - 32px;
+                    }
+                }
         }
 
         // 通知