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/router/agent_static.go

@@ -0,0 +1,133 @@
+package router
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"go.uber.org/zap"
+)
+
+type agentStaticPaths struct {
+	binDir    string
+	deployDir string
+}
+
+var agentBinaryFiles = map[string]string{
+	"linux-amd64":  "aiops-agent-linux-amd64",
+	"linux-arm64":  "aiops-agent-linux-arm64",
+	"darwin-arm64": "aiops-agent-darwin-arm64",
+}
+
+// registerAgentDownloads 注册 Agent 安装脚本和二进制下载路由，避免维护 backend/agent 重复目录。 // Logan.Li
+func registerAgentDownloads(r *gin.Engine, log *zap.Logger) {
+	paths := resolveAgentStaticPaths(log)
+
+	r.GET("/agent/arch", func(c *gin.Context) {
+		base := requestBaseURL(c)
+		downloads := availableAgentDownloads(paths.binDir)
+		c.JSON(http.StatusOK, gin.H{
+			"version":   "1.0.0",
+			"downloads": downloads,
+			"install":   fmt.Sprintf("curl -fsSL %s/agent/install.sh | sudo bash -s -- --server %s --token <token>", base, base),
+		})
+	})
+
+	r.GET("/agent/install.sh", func(c *gin.Context) {
+		serveAgentStaticFile(c, paths.deployDir, "install.sh")
+	})
+	for _, fileName := range agentBinaryFiles {
+		name := fileName
+		r.GET("/agent/"+name, func(c *gin.Context) {
+			serveAgentStaticFile(c, paths.binDir, name)
+		})
+	}
+	r.GET("/agent/bin/:file", func(c *gin.Context) {
+		serveAgentStaticFile(c, paths.binDir, c.Param("file"))
+	})
+	r.GET("/api/agent/bin/:file", func(c *gin.Context) {
+		serveAgentStaticFile(c, paths.binDir, c.Param("file"))
+	})
+}
+
+// resolveAgentStaticPaths 按部署形态寻找唯一 Agent 资源目录：容器优先，其次项目根目录。 // Logan.Li
+func resolveAgentStaticPaths(log *zap.Logger) agentStaticPaths {
+	paths := agentStaticPaths{
+		binDir: firstExistingDir([]string{
+			"/app/agent/bin",
+			"./agent/bin",
+			"../agent/bin",
+		}),
+		deployDir: firstExistingDir([]string{
+			"/app/agent/deploy",
+			"./agent/deploy",
+			"../agent/deploy",
+		}),
+	}
+	if log != nil {
+		log.Info("Agent 静态资源目录已解析",
+			zap.String("bin_dir", paths.binDir),
+			zap.String("deploy_dir", paths.deployDir),
+		)
+	}
+	return paths
+}
+
+func firstExistingDir(candidates []string) string {
+	for _, candidate := range candidates {
+		info, err := os.Stat(candidate)
+		if err == nil && info.IsDir() {
+			return candidate
+		}
+	}
+	return ""
+}
+
+func availableAgentDownloads(binDir string) gin.H {
+	downloads := gin.H{}
+	for platform, fileName := range agentBinaryFiles {
+		if binDir == "" {
+			continue
+		}
+		fullPath := filepath.Join(binDir, fileName)
+		if info, err := os.Stat(fullPath); err == nil && !info.IsDir() {
+			downloads[platform] = "/agent/" + fileName
+		}
+	}
+	return downloads
+}
+
+func requestBaseURL(c *gin.Context) string {
+	scheme := "http"
+	if c.Request.TLS != nil {
+		scheme = "https"
+	}
+	if proto := c.GetHeader("X-Forwarded-Proto"); proto != "" {
+		scheme = proto
+	}
+	host := c.Request.Host
+	if host == "" {
+		host = "localhost:8080"
+	}
+	return fmt.Sprintf("%s://%s", scheme, host)
+}
+
+func serveAgentStaticFile(c *gin.Context, dir string, fileName string) {
+	if dir == "" {
+		c.JSON(http.StatusNotFound, gin.H{"error": "agent static directory not found"})
+		return
+	}
+	if strings.Contains(fileName, "/") || strings.Contains(fileName, "\\") || fileName == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid agent file"})
+		return
+	}
+	fullPath := filepath.Join(dir, fileName)
+	if info, err := os.Stat(fullPath); err != nil || info.IsDir() {
+		c.JSON(http.StatusNotFound, gin.H{"error": "agent file not found"})
+		return
+	}
+	c.File(fullPath)
+}