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>

lib/orm/postgresql.go

@@ -35,10 +35,10 @@ func NewPostgresql(conf *PostgresqlConfig, logwriter logger.Writer) *gorm.DB {
 	if err2 != nil {
 		fmt.Println(err2)
 	}
-	// SetMaxIdleConns 设置空闲连接池中连接的最大数量
+	// SetMaxIdleConns sets the maximum number of connections in the idle connection pool
 	sqlDB.SetMaxIdleConns(conf.MaxIdleConns)
 
-	// SetMaxOpenConns 设置打开数据库连接的最大数量。
+	// SetMaxOpenConns sets the maximum number of open database connections.
 	sqlDB.SetMaxOpenConns(conf.MaxOpenConns)
 
 	return db