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/controller/credential_assign.go

@@ -74,6 +74,23 @@ func applyCredential(cred model.Credential, plain string, server *model.Server)
 		server.SSHKey = privateKey
 		server.AuthType = "key"
 		server.Password = ""
+		server.Protocol = "ssh"
+		if server.OSType == "" {
+			server.OSType = "linux"
+		}
+	} else if cred.SecretType == "rdp" {
+		var rdpc model.RDPSecretContent
+		if json.Unmarshal([]byte(plain), &rdpc) == nil && rdpc.Username != "" {
+			server.Username = rdpc.Username
+		}
+		server.Password = plain
+		server.AuthType = "password"
+		server.SSHKey = ""
+		server.Protocol = "rdp"
+		server.OSType = "windows"
+		if server.RDPPort == 0 {
+			server.RDPPort = 3389
+		}
 	} else {
 		server.Password = plain
 		server.AuthType = "password"