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/rdp_cred.go

@@ -0,0 +1,35 @@
+package controller
+
+import (
+	"encoding/json"
+	"errors"
+
+	"ezops/model"
+	"ezops/pkg/crypto"
+)
+
+// loadRDPCredential 解密并解析 Windows 服务器 RDP 凭据 // Logan.Li
+func loadRDPCredential(crypt *crypto.SecretBox, server model.Server) (model.RDPSecretContent, error) {
+	var cred model.RDPSecretContent
+	if server.Password == "" {
+		return cred, errors.New("该 Windows 资产未关联 RDP 凭据")
+	}
+	plain := server.Password
+	if dec, err := crypt.Decrypt(server.Password); err == nil {
+		plain = dec
+	}
+	if err := json.Unmarshal([]byte(plain), &cred); err != nil {
+		cred.Username = server.Username
+		cred.Password = plain
+	}
+	if cred.Username == "" {
+		cred.Username = server.Username
+	}
+	if cred.Security == "" {
+		cred.Security = "nla"
+	}
+	if cred.Username == "" || cred.Password == "" {
+		return cred, errors.New("RDP 凭据缺少用户名或密码")
+	}
+	return cred, nil
+}