- Add command support for plugin management
- Optimize plugin management page layout
- Add email copy functionality for users
- Convert payment methods and Telegram Bot to plugin system
- Unify protocol filter configuration to client.type.field (dot-path, three-segment) format, support strict whitelist mode
- Refactor AbstractProtocol and all protocol classes for more flexible and maintainable subscription delivery
- Change payment callback logic: use origin_url concatenation instead of return_url for more accurate redirects
