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>

frontend/src/locales/en-US.json

@@ -528,10 +528,8 @@
     "dashboard": "Dashboard",
     "assets": "Assets",
     "servers": "Servers",
-    "cloudAccounts": "Cloud Accounts",
+    "cloudAccounts": "Multi-Cloud Accounts",
     "domains": "Domains",
-    "regions": "Regions",
-    "platforms": "Cloud Platforms",
     "cloudBilling": "Cloud Billing",
     "kubernetes": "Kubernetes",
     "clusterList": "Clusters",
@@ -573,7 +571,7 @@
     "aiops": "AIOps",
     "aiAssistant": "AI Assistant",
     "aiAlertAnalyzer": "Alert Analysis",
-    "aiPredictive": "Capacity Forecast",
+    "aiPredictive": "Predictive Analytics",
     "aiAgentCli": "Agent CLI",
     "aiLlmConfig": "LLM Settings",
     "approval": "Requests",
@@ -2858,7 +2856,7 @@
     "peopleCount": "{{count}} people",
     "dashboard": {
       "title": "Monitoring Dashboard",
-      "subtitle": "Agent hosts, Zabbix, Prometheus and custom dashboards",
+      "subtitle": "Unified monitoring for Agent hosts, Zabbix and Prometheus",
       "tab": {
         "agent": "Agent Hosts",
         "dashboard": "Custom"
@@ -5552,7 +5550,7 @@
     "stopped": "Stopped",
     "error": "Error",
     "searchAccount": "Search account name or AccessKey...",
-    "accountsSubtitle": "Manage multi-cloud access credentials and account info",
+    "accountsSubtitle": "Connect cloud providers via AK to sync regions, hosts and billing",
     "noAccountData": "No cloud account data",
     "monthlyFee": "Monthly Fee",
     "serverCount": "Servers",
@@ -5561,10 +5559,25 @@
     "saveChanges": "Save Changes",
     "createAccount": "Create Account",
     "editAccountDesc": "Modify account info and credentials. Leave blank to keep existing.",
-    "addAccountDesc": "Enter multi-cloud credentials for resource sync and cost tracking",
+    "addAccountDesc": "Enter cloud provider credentials for resource sync and cost tracking",
     "accountNamePlaceholder": "e.g. Aliyun Production",
-    "platformLabel": "Cloud Platform",
-    "allPlatforms": "All Platforms",
+    "providerLabel": "Provider",
+    "allProviders": "All Providers",
+    "platformLabel": "Provider",
+    "allPlatforms": "All Providers",
+    "tabOverview": "Overview",
+    "tabRegions": "Regions",
+    "tabBilling": "Billing",
+    "syncRegions": "Sync Regions",
+    "syncBilling": "Sync Billing",
+    "syncRegionsSuccess": "Regions synced",
+    "syncRegionsFailed": "Region sync failed",
+    "importHosts": "Import Hosts",
+    "regionCount": "Regions",
+    "noRegions": "No regions yet — sync first",
+    "noBillingRecords": "No billing records this month",
+    "regionListHint": "Account regions (from cloud API sync)",
+    "billingMonthHint": "Billing details this month",
     "loadStatsFailed": "Failed to load statistics",
     "loadBillingFailed": "Failed to load billing",
     "loadAlertRulesFailed": "Failed to load alert rules",
@@ -5576,6 +5589,14 @@
     "endDate": "End Date",
     "query": "Query",
     "billingSubtitle": "Multi-cloud cost statistics, records and alerts",
+    "syncYesterday": "Sync Yesterday",
+    "syncBillingHint": "Pull yesterday's bill from cloud accounts with AK configured",
+    "syncBillingInfo": "Sync pulls bills from active cloud accounts (product + region). Aliyun supported now.",
+    "syncBillingTiming": "Billing latency: Aliyun daily bills are usually T+1 (sync yesterday after 10:00 today). Postpaid hourly products may lag ~1 day. AK needs bss:DescribeBillList.",
+    "syncBillingSuccess": "Billing sync succeeded",
+    "syncBillingPartial": "Some accounts failed to sync",
+    "syncBillingFailed": "Billing sync failed",
+    "syncBillingResult": "{{date}}: {{created}} created, {{updated}} updated",
     "today": "Today",
     "thisMonth": "This Month",
     "yearly": "Yearly",