feat: remove unused plugin version comparison and types, refactor proxy server to support authentication

- Deleted version comparison logic from `pkg/plugin/sign/version.go`.
- Removed unused types and constants from `pkg/plugin/types.go`.
- Updated `pkg/protocol/message.go` to remove plugin-related message types.
- Enhanced `pkg/proxy/http.go` and `pkg/proxy/socks5.go` to include username/password authentication for HTTP and SOCKS5 proxies.
- Modified `pkg/proxy/server.go` to pass authentication parameters to server constructors.
- Added new API endpoint to generate installation commands with a token for clients.
- Created database functions to manage installation tokens in `internal/server/db/install_token.go`.
- Implemented the installation command generation logic in `internal/server/router/handler/install.go`.
- Updated web frontend to support installation command generation and display in `web/src/views/ClientsView.vue`.

CLAUDE.md

@@ -61,13 +61,7 @@ pkg/
   ├── auth/          # JWT authentication
   ├── utils/         # Port availability checking
   ├── version/       # Version info and update checking (Gitea API)
-  ├── update/        # Shared update logic (download, extract tar.gz/zip)
-  └── plugin/        # Plugin system core
-      ├── types.go       # Plugin interfaces
-      ├── registry.go    # Plugin registry
-      ├── script/        # JS plugin runtime (goja)
-      ├── sign/          # Plugin signature verification
-      └── store/         # Plugin persistence (SQLite)
+  └── update/        # Shared update logic (download, extract tar.gz/zip)
 web/                 # Vue 3 + TypeScript frontend (Vite + naive-ui)
 scripts/             # Build scripts (build.sh, build.ps1)
 ```
@@ -75,23 +69,16 @@ scripts/             # Build scripts (build.sh, build.ps1)
 ### Key Interfaces
 
 - `ClientStore` (internal/server/db/): Database abstraction for client rules storage
-- `JSPluginStore` (internal/server/db/): JS plugin persistence
 - `ServerInterface` (internal/server/router/handler/): API handler interface
-- `ClientPlugin` (pkg/plugin/): Plugin interface for client-side plugins
 
 ### Proxy Types
 
-**内置类型** (直接在 tunnel 中处理):
 1. **TCP** (default): Direct port forwarding (remote_port → local_ip:local_port)
 2. **UDP**: UDP port forwarding
 3. **HTTP**: HTTP proxy through client network
 4. **HTTPS**: HTTPS proxy through client network
 5. **SOCKS5**: SOCKS5 proxy through client network
 
-**JS 插件类型** (通过 goja 运行时):
-- Custom application plugins (file-server, api-server, etc.)
-- Runs on client side with sandbox restrictions
-
 ### Data Flow
 
 External User → Server Port → Yamux Stream → Client → Local Service
@@ -102,44 +89,6 @@ External User → Server Port → Yamux Stream → Client → Local Service
 - Client: Command-line flags only (server address, token, client ID)
 - Default ports: 7000 (tunnel), 7500 (web console)
 
-## Plugin System
-
-GoTunnel supports a JavaScript-based plugin system using the goja runtime.
-
-### Plugin Architecture
-
-- **内置协议**: tcp, udp, http, https, socks5 直接在 tunnel 代码中处理
-- **JS Plugins**: 自定义应用插件通过 goja 运行时在客户端执行
-- **Plugin Store**: 从官方商店浏览和安装插件
-- **Signature Verification**: 插件需要签名验证才能运行
-
-### JS Plugin Lifecycle
-
-```javascript
-function metadata() {
-    return {
-        name: "plugin-name",
-        version: "1.0.0",
-        type: "app",
-        description: "Plugin description",
-        author: "Author"
-    };
-}
-
-function start() { /* called on plugin start */ }
-function handleConn(conn) { /* handle each connection */ }
-function stop() { /* called on plugin stop */ }
-```
-
-### Plugin APIs
-
-- **Basic**: `log()`, `config()`
-- **Connection**: `conn.Read()`, `conn.Write()`, `conn.Close()`
-- **File System**: `fs.readFile()`, `fs.writeFile()`, `fs.readDir()`, `fs.stat()`, etc.
-- **HTTP**: `http.serve()`, `http.json()`, `http.sendFile()`
-
-See `PLUGINS.md` for detailed plugin development documentation.
-
 ## API Documentation
 
 The server provides Swagger-documented REST APIs at `/api/`.