feat(ios,p0): iOS P0 platform, audio fixes, channel UX

apps/chanora_flutter/lib/l10n/app_zh.arb

@@ -37,6 +37,7 @@
   "pttCapabilityExplainGoGlobalWindows": "在 Windows 上，绑定按键后会自动启用全局对讲，无需额外权限。",
   "pttCapabilityExplainGoGlobalMacos": "在 macOS 上，启用全局对讲需要「输入监视」权限。请打开「系统设置 → 隐私与安全 → 输入监视」，授权 Chanora 后重新绑定按键。",
   "pttCapabilityExplainGoGlobalLinux": "在 Linux 上，启用全局对讲需要带 GlobalShortcuts 门户的 GNOME-Wayland 桌面。请重新绑定按键，并在桌面弹出快捷键对话框时接受。",
+  "pttCapabilityExplainGoGlobalIos": "在 iOS 上，Apple 不向应用开放全局热键。Chanora 使用屏幕上的按住说话按钮，并且仅在应用位于前台时响应。",
   "pttCapabilityExplainGoGlobalGeneric": "当前环境暂不支持全局对讲。聚焦对讲在 Chanora 窗口获得焦点时仍可正常使用。",
   "pttConfigureAction": "配置",
   "pttConfigureTitle": "配置对讲按键",
@@ -51,6 +52,7 @@
   "outputMuteAction": "静音扬声器",
   "outputUnmuteAction": "取消扬声器静音",
   "joinChannelAction": "加入频道",
+  "leaveChannelAction": "离开频道",
   "channelPasswordTitle": "频道密码",
   "bookmarksHeading": "书签",
   "bookmarksEmpty": "尚无书签。先在上方填写服务器，然后点击“保存书签”。",
@@ -97,6 +99,7 @@
   "audioRouteCarAudio": "车载音频",
   "audioRouteAirplay": "AirPlay",
   "audioRouteUnknown": "未知",
+  "channelJoinAlreadyIn": "您已在此频道中。",
   "channelJoinFailedPermission": "权限不足，无法加入此频道。",
   "channelJoinFailedPassword": "频道密码错误。",
   "channelJoinFailedFull": "频道已满。",