feat(remote): 修复键盘输入映射并重构连接流程

- Android端注入按键时显式设置SOURCE_KEYBOARD，修复IME丢弃事件导致输入框无法输入文字的问题
- Flutter端新增Flutter逻辑键到Android keyCode的转换映射，避免功能键误触发
- 重构RemoteController，分离信令连接与远程控制逻辑，支持设备列表选择与配对码兑换
- AuthRepository接口新增getBindings、getOnlineDevices、redeemPairingCode方法
- DioAuthRepository实现401自动刷新token重试机制
- ConnectionSessionState扩展设备列表、在线状态、配对码等状态字段

webrtc_controller_flutter/lib/l10n/app_zh.arb

@@ -13,8 +13,7 @@
   "connecting": "正在连接...",
   "loginAccount": "登录账号",
   "connectDevice": "连接被控设备",
-  "serverUrl": "信令服务器地址:",
-  "serverUrlPlaceholder": "wss://www.ttstd.com/signal",
+
   "deviceId": "本机设备ID（连接后由服务端下发，无需填写）:",
   "deviceIdPlaceholder": "连接后由服务端下发",
   "targetDeviceId": "目标被控设备ID:",
@@ -23,7 +22,7 @@
   "password": "密码",
   "loginFailed": "登录失败：{error}",
   "usernamePasswordRequired": "请输入用户名和密码",
-  "serverAndTargetRequired": "请填写服务器地址和目标设备ID",
+  "targetRequired": "请填写目标设备ID",
   "authTitle": "连接鉴权",
   "authNone": "免密连接",
   "authNoneDesc": "被控端弹出手动确认框，无需验证码或密码",
@@ -67,5 +66,16 @@
   "forceLogout": "账号已在其他位置登录，已强制下线。",
   "loginFirst": "请先登录后再连接",
   "pleaseFillAuth": "请输入验证码或密码",
-  "streamModeSelfCodecDesc": "当前平台不支持自编码硬解。"
+  "streamModeSelfCodecDesc": "当前平台不支持自编码硬解。",
+  "boundDevices": "已绑定设备",
+  "online": "在线",
+  "offline": "离线",
+  "noBoundDevices": "暂无已绑定设备",
+  "refreshDevices": "刷新",
+  "redeemPairingCode": "使用配对码绑定",
+  "pairingCodeHint": "请输入被控端显示的配对码",
+  "bindingFailed": "绑定失败：{error}",
+  "deviceOfflineCannotConnect": "设备「{name}」当前不在线，无法连接",
+  "pleaseSelectDevice": "请先选择一个绑定的设备",
+  "bindSuccess": "绑定成功"
 }