i18n: Translate all Chinese to English across the codebase

Translate Chinese comments, log/error messages, validator labels and
Swagger annotations to English throughout the source code, generated
Swagger docs, config files and CI workflows.

Make the English README primary: README.md now holds the English docs
and README_EN.md holds the Chinese version, with cross-language links
updated accordingly.

Note: the generated docs/ swagger files were translated in place; run
`go generate ./...` (swag init) to regenerate them from the now-English
annotations when a Go toolchain is available.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

http/response/api/webClient.go

@@ -22,7 +22,7 @@ type WebClientPeerInfoPayload struct {
 
 func (wcpp *WebClientPeerPayload) FromAddressBook(a *model.AddressBook) {
 	wcpp.ViewStyle = "shrink"
-	//24小时前
+	//24 hours ago
 	wcpp.Tm = time.Now().Add(-time.Hour * 24).UnixNano()
 	wcpp.Info = WebClientPeerInfoPayload{
 		Username: a.Username,
@@ -34,7 +34,7 @@ func (wcpp *WebClientPeerPayload) FromAddressBook(a *model.AddressBook) {
 
 func (wcpp *WebClientPeerPayload) FromShareRecord(sr *model.ShareRecord) {
 	wcpp.ViewStyle = "shrink"
-	//24小时前
+	//24 hours ago
 	wcpp.Tm = time.Now().UnixNano()
 	wcpp.Tmppwd = sr.Password
 	wcpp.Info = WebClientPeerInfoPayload{