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>

docker-compose.yaml

@@ -13,5 +13,5 @@ services:
     volumes:
       - ./data/rustdesk/api:/app/data # database
       # - ./conf:/app/conf # config
-      # - ./resources:/app/resources # 静态资源
+      # - ./resources:/app/resources # static resources
     restart: unless-stopped