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/rdp/session_connect.go

@@ -0,0 +1,169 @@
+package rdp
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"time"
+
+	"ezops/pkg/rdp/credssp"
+	"ezops/pkg/rdp/transport"
+)
+
+// Session 保存已建立的 RDP 图形会话状态 // Logan.Li
+type Session struct {
+	Conn     io.ReadWriter
+	UserID   uint16
+	SharedID uint32
+	Width    int
+	Height   int
+}
+
+// OpenSession 完成 CredSSP + MCS/GCC 握手并进入可收帧状态 // Logan.Li
+func OpenSession(ctx context.Context, cfg Config) (*Session, error) {
+	port := cfg.Port
+	if port == 0 {
+		port = 3389
+	}
+	if cfg.MCSMode == "" {
+		cfg.MCSMode = strings.TrimSpace(os.Getenv("RDP_MCS_MODE"))
+	}
+	if cfg.MCSMode == "" {
+		cfg.MCSMode = "grdp-modern"
+	}
+	address := fmt.Sprintf("%s:%d", cfg.Host, port)
+	strategies := []credssp.Options{
+		{Version: 6, PubKeyStyle: "binding"},
+		{Version: 6, PubKeyStyle: "binding", UseCBT: true},
+		{Version: 6, PubKeyStyle: "binding", ForceMIC: true},
+		{Version: 2, PubKeyStyle: "raw"},
+	}
+	var lastErr error
+	for _, opts := range strategies {
+		sess, err := openSessionOnce(ctx, cfg, address, opts)
+		if err == nil {
+			return sess, nil
+		}
+		lastErr = err
+	}
+	if lastErr == nil {
+		lastErr = fmt.Errorf("RDP 会话建立失败")
+	}
+	return nil, lastErr
+}
+
+func openSessionOnce(ctx context.Context, cfg Config, address string, opts credssp.Options) (*Session, error) {
+	tlsConn, _, err := dialCredSSPOnce(ctx, cfg, address, opts)
+	if err != nil {
+		return nil, err
+	}
+	_ = tlsConn.SetDeadline(time.Now().Add(45 * time.Second))
+	if err := transport.WriteX224Data(tlsConn, buildMCSConnectInitial(cfg)); err != nil {
+		_ = tlsConn.Close()
+		return nil, err
+	}
+	payload, err := transport.ReadX224Data(tlsConn)
+	if err != nil {
+		_ = tlsConn.Close()
+		return nil, err
+	}
+	if _, err := parseMCSConnectResponse(payload); err != nil {
+		_ = tlsConn.Close()
+		return nil, err
+	}
+	userID, err := attachMCSUser(tlsConn)
+	if err != nil {
+		_ = tlsConn.Close()
+		return nil, err
+	}
+	mcsInfo, _ := parseMCSConnectResponse(payload)
+	joinIDs := append([]uint16{mcsGlobalChannelID, userID}, mcsInfo.ServerChannelIDs...)
+	for _, channelID := range joinIDs {
+		if _, err := joinMCSChannel(tlsConn, userID, channelID); err != nil {
+			_ = tlsConn.Close()
+			return nil, err
+		}
+	}
+	_, demand, err := sendClientInfoAndReadDemand(tlsConn, cfg, userID)
+	if err != nil {
+		_ = tlsConn.Close()
+		return nil, err
+	}
+	if _, err := sendConfirmActiveAndFinalize(tlsConn, cfg, userID, demand); err != nil {
+		_ = tlsConn.Close()
+		return nil, err
+	}
+	if err := requestDisplayUpdates(tlsConn, cfg, userID, demand.sharedID); err != nil {
+		_ = tlsConn.Close()
+		return nil, err
+	}
+	width := cfg.Width
+	if width <= 0 {
+		width = 1280
+	}
+	height := cfg.Height
+	if height <= 0 {
+		height = 800
+	}
+	_ = tlsConn.SetDeadline(time.Time{})
+	return &Session{
+		Conn:     tlsConn,
+		UserID:   userID,
+		SharedID: demand.sharedID,
+		Width:    width,
+		Height:   height,
+	}, nil
+}
+
+func requestDisplayUpdates(rw io.ReadWriter, cfg Config, userID uint16, sharedID uint32) error {
+	if conn, ok := rw.(interface{ SetReadDeadline(time.Time) error }); ok {
+		_ = conn.SetReadDeadline(time.Now().Add(3 * time.Second))
+		pkt, err := ReadWirePacket(rw)
+		_ = conn.SetReadDeadline(time.Time{})
+		if err == nil && !pkt.FastPath {
+			_, _ = parseMCSDataIndication(pkt.Payload)
+		}
+	}
+	body := buildSuppressOutputBody(cfg, true)
+	pdu := buildDataPDU(userID, sharedID, pduType2SuppressOutput, body)
+	if err := transport.WriteX224Data(rw, buildMCSSendDataRequest(userID, mcsGlobalChannelID, pdu)); err != nil {
+		return fmt.Errorf("发送 SuppressOutput 失败: %w", err)
+	}
+	return nil
+}
+
+func buildSuppressOutputBody(cfg Config, allow bool) []byte {
+	width := cfg.Width
+	if width <= 0 {
+		width = 1280
+	}
+	height := cfg.Height
+	if height <= 0 {
+		height = 800
+	}
+	out := make([]byte, 0, 12)
+	if allow {
+		out = append(out, 1, 0, 0, 0)
+	} else {
+		out = append(out, 0, 0, 0, 0)
+	}
+	out = append(out, 0, 0, 0, 0, byte(width-1), byte((width-1)>>8), byte(height-1), byte((height-1)>>8))
+	return out
+}
+
+func buildRefreshRectBody(cfg Config) []byte {
+	width := cfg.Width
+	if width <= 0 {
+		width = 1280
+	}
+	height := cfg.Height
+	if height <= 0 {
+		height = 800
+	}
+	out := make([]byte, 0, 10)
+	out = append(out, 1, 0)
+	out = append(out, 0, 0, 0, 0, byte(width-1), byte((width-1)>>8), byte(height-1), byte((height-1)>>8))
+	return out
+}