Refactor localization strings to English across various services and UI components

- Updated titles and subtitles in channel_service.go for web channel and WeChat MP channel configurations.
- Changed handoff messages in conversation_human_dispatch_service.go to English.
- Modified notification messages in event handlers for ticket and conversation assignments to English.
- Adjusted ticket creation messages in ticket_service.go to reflect English localization.
- Updated default locale settings in i18n configuration files to English (en-US).
- Changed HTML language attribute in layout.tsx to English.
- Refactored widget locale detection logic in agent-desk-sdk.ts to prioritize English.

internal/pkg/i18nx/bundle.go

@@ -20,7 +20,7 @@ var (
 
 func Bundle() *i18n.Bundle {
 	bundleOnce.Do(func() {
-		b := i18n.NewBundle(language.SimplifiedChinese)
+		b := i18n.NewBundle(language.AmericanEnglish)
 		b.RegisterUnmarshalFunc("toml", toml.Unmarshal)
 		for _, name := range []string{
 			"locales/active.zh-CN.toml",