feat(rdp): 新增 RDP 远程桌面/SMB/账单同步能力 + 清理编译产物

主要变更：
- RDP 远程桌面：新增 backend/pkg/rdp（RDP 引擎 + credssp/display/rle/trace）、
  backend/controller/rdp*（连接/凭证/文件/会话/实时）、frontend RDP 组件与 API
- Windows SMB 文件传输：backend/pkg/winsmb
- 云账单同步：backend/pkg/billingsync + billing_sync/aliyun_billing，前端账单详情
- Agent CLI Kubernetes 工具：kubernetes_action/get、pod_execute/logs
- 服务器导入助手：server_import_helpers、ImportCredentialSettings
- 国际化与组件重构（cloud/deploy/monitor/server/system 等多模块）
- 清理编译产物二进制：移除 backend/server、backend/agent/bin/aiops-agent-*
- .gitignore：新增 backend/agent/ 与 .cache/（避免 334MB go-build 缓存误入库）

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

backend/pkg/wshub/manager.go

@@ -23,12 +23,13 @@ import (
 
 // Connection types — identifies which feature a WebSocket serves.
 const (
-	TypeTerminal  = "terminal"   // WebShell SSH terminal
-	TypeKubectl   = "kubectl"    // kubectl command terminal
-	TypePodExec   = "pod_exec"   // K8s pod exec terminal
-	TypeAudit     = "audit"      // Audit real-time stream (live monitor)
-	TypeMetrics   = "metrics"    // Dashboard metrics push
-	TypePipeline  = "pipeline"   // Pipeline run log stream
+	TypeTerminal = "terminal" // WebShell SSH terminal
+	TypeRDP      = "rdp"      // RDP 图形会话 // Logan.Li
+	TypeKubectl  = "kubectl"  // kubectl command terminal
+	TypePodExec  = "pod_exec" // K8s pod exec terminal
+	TypeAudit    = "audit"    // Audit real-time stream (live monitor)
+	TypeMetrics  = "metrics"  // Dashboard metrics push
+	TypePipeline = "pipeline" // Pipeline run log stream
 )
 
 // Config tunes the manager behavior.
@@ -88,8 +89,8 @@ type WSManager struct {
 	conns sync.Map // id → *ConnInfo
 	next  uint64   // atomic counter for connection IDs
 
-	mu       sync.Mutex
-	closed   bool
+	mu     sync.Mutex
+	closed bool
 }
 
 // New creates a WSManager with the given config.