feat: 新增常规设置页面，支持关闭行为与语言切换

新增常规设置路由和页面，实现关闭行为（每次询问/保持选择）与应用语言的持久化配置；封装卡片式单选组组件复用在关闭弹窗和设置页；修改关闭逻辑，根据关闭行为决定是否显示确认弹窗，同步更新多语言文案和类型定义。

src/i18n/locales/en-US.json

@@ -39,7 +39,12 @@
     "tray": "Minimize to system tray",
     "trayDesc": "Keep Frpilot running in the background; reopen it from the system tray",
     "exit": "Quit directly",
-    "exitDesc": "Stop the tunnel and exit Frpilot completely"
+    "exitDesc": "Stop the tunnel and exit Frpilot completely",
+    "behavior": "Close behavior",
+    "ask": "Ask every time",
+    "askDesc": "Show this dialog on every close and let you choose",
+    "remember": "Keep the choice above",
+    "rememberDesc": "Remember the close method above and never ask again"
   },
   "system": {
     "cpu": "CPU usage",
@@ -73,9 +78,20 @@
     "title": "Settings",
     "placeholder": "The settings page is under construction.",
     "menu": {
+      "general": "General",
       "appearance": "Appearance",
       "about": "About"
     },
+    "general": {
+      "title": "General",
+      "subtitle": "Basic settings such as close behavior and app language",
+      "closeBehavior": "Close behavior",
+      "closeBehaviorTip": "Choose what happens when you click the close button. Kept in sync with the close dialog.",
+      "closeAction": "Close method",
+      "closeActionTip": "Takes effect when \"Keep the choice above\" is selected. The window closes this way directly, and it is also the default option in the close dialog.",
+      "language": "Language",
+      "languageTip": "Switch the interface language. In sync with the language switcher in the title bar."
+    },
     "appearance": {
       "title": "Appearance",
       "subtitle": "Customize the theme mode and window background",