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/main.go

@@ -19,6 +19,7 @@ import (
 	"ezops/seed"
 	"ezops/pkg/appdir"
 	"ezops/pkg/auditcleaner"
+	"ezops/pkg/billingsync"
 	"ezops/pkg/database"
 	snmppkg "ezops/pkg/snmp"
 	"ezops/pkg/cronscheduler"
@@ -304,6 +305,42 @@ func main() {
 		}
 	}()
 
+	// 每日 10:30 同步云账号昨日账单（阿里云 T+1 出账） // Logan.Li
+	go func() {
+		runBillingSync := func() {
+			start := time.Now()
+			result := billingsync.SyncDate(db, billingsync.Yesterday(), nil)
+			msg := billingsync.SummaryMessage(result)
+			status := "success"
+			if result.Accounts == 0 {
+				status = "failed"
+				msg = "没有可同步的活跃云账号"
+			} else if result.Created == 0 && result.Updated == 0 && len(result.Errors) > 0 {
+				status = "failed"
+				msg = result.Errors[0]
+			} else if len(result.Errors) > 0 {
+				msg += "；" + result.Errors[0]
+			}
+			systask.Record("cloud_billing_sync", status, msg, time.Since(start))
+			if status == "success" && (result.Created > 0 || result.Updated > 0) {
+				log.Info("云账单定时同步完成",
+					zap.String("date", result.BillingDate),
+					zap.Int("created", result.Created),
+					zap.Int("updated", result.Updated),
+				)
+			}
+		}
+		for {
+			now := time.Now()
+			next := time.Date(now.Year(), now.Month(), now.Day(), 10, 30, 0, 0, now.Location())
+			if !now.Before(next) {
+				next = next.Add(24 * time.Hour)
+			}
+			time.Sleep(time.Until(next))
+			runBillingSync()
+		}
+	}()
+
 	// 前端静态文件服务（go:embed 模式，二进制部署用） // Logan.Li
 	setupFrontend(r)