feat(channel): redesign guest mode warning dialog

- Reorder buttons: Confirm (primary) > Switch to Private > Disable Guest Mode (small gray)
- Update title and description to focus on visibility impact
- Add confirm key to en/zh locales; remove dont_remind key

public/locales/en/chat.json

@@ -79,10 +79,10 @@
   "remark_placeholder": "Set Nickname",
 
   "guest_mode_warning": {
-    "title": "Guest Mode is Enabled",
-    "desc": "Unauthenticated visitors can see messages in public channels. You may disable guest mode or switch to a private channel instead.",
+    "title": "This Channel Will Be Visible to Guests",
+    "desc": "If you continue, guest users may be able to see messages in this public channel.",
+    "confirm": "Confirm",
     "disable_guest": "Disable Guest Mode",
-    "switch_private": "Switch to Private Channel",
-    "dont_remind": "Don't remind me again"
+    "switch_private": "Switch to Private Channel"
   }
 }

public/locales/zh/chat.json

@@ -78,10 +78,10 @@
   "remark_placeholder": "备注该用户",
 
   "guest_mode_warning": {
-    "title": "访客模式已开启",
-    "desc": "未登录的访客可以看到公共频道的消息流。您可以前往关闭访客模式，或改为创建私有频道。",
+    "title": "该频道将对访客可见",
+    "desc": "继续创建后，访客用户可能会看到该公共频道中的消息。",
+    "confirm": "确认创建",
     "disable_guest": "关闭访客模式",
-    "switch_private": "改为私有频道",
-    "dont_remind": "不再提醒"
+    "switch_private": "改为私有频道"
   }
 }