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/credssp/pubkey_test.go

@@ -0,0 +1,55 @@
+package credssp
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"math/big"
+	"testing"
+	"time"
+)
+
+func TestSubjectPublicKeyDiffersFromPKIX(t *testing.T) {
+	key, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		t.Fatal(err)
+	}
+	certDER, err := x509.CreateCertificate(rand.Reader, &x509.Certificate{
+		SerialNumber: big.NewInt(1),
+		Subject:      pkix.Name{CommonName: "rdp-test"},
+		NotBefore:    time.Now().Add(-time.Hour),
+		NotAfter:     time.Now().Add(time.Hour),
+	}, &x509.Certificate{
+		SerialNumber: big.NewInt(1),
+		Subject:      pkix.Name{CommonName: "rdp-test"},
+		NotBefore:    time.Now().Add(-time.Hour),
+		NotAfter:     time.Now().Add(time.Hour),
+	}, &key.PublicKey, key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cert, err := x509.ParseCertificate(certDER)
+	if err != nil {
+		t.Fatal(err)
+	}
+	subjectKey, err := subjectPublicKey(cert)
+	if err != nil {
+		t.Fatal(err)
+	}
+	pkixKey, err := x509.MarshalPKIXPublicKey(cert.PublicKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(subjectKey) == string(pkixKey) {
+		t.Fatal("SubjectPublicKey 不应等于完整 SPKI")
+	}
+	rsaDER, err := asn1.Marshal(*cert.PublicKey.(*rsa.PublicKey))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(subjectKey) != string(rsaDER) {
+		t.Fatalf("SubjectPublicKey 应与 RSA PKCS#1 DER 一致，len=%d/%d", len(subjectKey), len(rsaDER))
+	}
+}