chore: remove unnecessary sections from system status page

internal/web/ui/templates/system.html

@@ -1,27 +1,7 @@
 {{define "system"}}
 <div class="card">
   <div class="crumb">系统管理 / 系统状态</div>
-  <div class="muted small" style="margin-top:8px">系统状态页负责平台健康、发现机制和接入策略查看。</div>
-</div>
-
-<div class="detail-grid">
-  <div class="card">
-    <h2 class="title-with-icon">{{icon "discovery"}}<span>设备发现与注册</span></h2>
-    <div class="info-list">
-      <div><span>当前设备数</span><strong>{{len .Devices}}</strong></div>
-      <div><span>发现方式</span><strong>UDP 广播发现</strong></div>
-      <div><span>注册方式</span><strong>自动发现 / 手动录入</strong></div>
-    </div>
-  </div>
-
-  <div class="card">
-    <h2 class="title-with-icon">{{icon "shield"}}<span>Agent 访问策略</span></h2>
-    <div class="info-list">
-      <div><span>访问模型</span><strong>统一令牌</strong></div>
-      <div><span>更新方式</span><strong>部署脚本托管</strong></div>
-      <div><span>页面策略</span><strong>默认不暴露敏感值</strong></div>
-    </div>
-  </div>
+  <div class="muted small" style="margin-top:8px">系统状态页负责平台健康检查和数据备份恢复。</div>
 </div>
 
 <div class="detail-grid">
@@ -36,14 +16,6 @@
       <a class="btn ghost" href="/openapi.json">OpenAPI</a>
     </div>
   </div>
-
-  <div class="card">
-    <h2 class="title-with-icon">{{icon "tech"}}<span>当前纳管设备</span></h2>
-    <div class="info-list compact-list">
-      <div><span>在线设备</span><strong>{{len .Devices}}</strong></div>
-      <div><span>接入端口</span><strong class="mono">9100 / 9000</strong></div>
-    </div>
-  </div>
 </div>
 
 <div class="detail-grid">

internal/web/ui_test.go

@@ -3414,7 +3414,7 @@ func TestUI_AuditAndSystemPagesDefineNewScopes(t *testing.T) {
 
 	rrSystem := httptest.NewRecorder()
 	ui.pageSystem(rrSystem, httptest.NewRequest(http.MethodGet, "/ui/system", nil))
-	for _, want := range []string{"系统管理 / 系统状态", "设备发现与注册", "Agent 访问策略", "后台健康", "当前设备数", "UDP 广播发现", "/health", "/openapi.json"} {
+	for _, want := range []string{"系统管理 / 系统状态", "后台健康", "数据备份 / 恢复", "/health", "/openapi.json"} {
 		if !strings.Contains(rrSystem.Body.String(), want) {
 			t.Fatalf("expected system HTML to contain %q", want)
 		}