feat(R2)+refactor: 平台管理分区 + 删 3 桩页（档案80 #7）+ 无浏览器验收脚本

- R2：business-plugins 0.2.9 新增原生「平台管理」只读分区（已铺发到 admin/guest profile 并生效）
- 档案80 #7：删 web/{desktop,plugins,skills}.html（9→6 页）+ 5 处引用改直达 portal（nginx 已加 301）
- 新增 scripts/verify-platform-admin-section.mjs（打桩 react/jsx-runtime 真执行 client.js 做渲染断言）并接入 npm run verify

web/admin.html

@@ -40,7 +40,7 @@
 
       <div id="console" class="hidden">
         <div class="row-actions" style="justify-content:space-between">
-          <span>登录为 <strong id="who"></strong> <a href="/skills.html" style="margin-left:10px">技能管理</a></span>
+          <span>登录为 <strong id="who"></strong> <a href="/portal.html#/skills" style="margin-left:10px">技能管理</a></span>
           <button class="btn ghost small" id="logoutBtn">退出</button>
         </div>
         <table class="admin">

web/desktop.html

@@ -1,11 +0,0 @@
-<!doctype html>
-<html lang="zh-CN">
-<head>
-<meta charset="utf-8" />
-<meta http-equiv="refresh" content="0;url=/portal.html" />
-<title>跳转中…</title>
-</head>
-<body>
-<script>location.replace('/portal.html')</script>
-</body>
-</html>

web/index.html

@@ -24,7 +24,7 @@
         } catch {
           // fall through to desktop
         }
-        location.href = '/desktop.html'
+        location.href = '/portal.html'
       })()
     </script>
   </body>

web/login.html

@@ -91,13 +91,13 @@
             location.href = b.url
             return
           }
-          // 失败兜底：admin 可手动进管理台 /desktop.html
+          // 失败兜底：admin 可手动进管理台 /portal.html
           const errText =
             b.error === 'instance_starting' ? '实例正在启动，请稍后重试'
             : (b.error ?? 'HTTP ' + r.status)
           msg.innerHTML =
             '进入工作台失败：' + errText +
-            (role === 'admin' ? '（<a href="/desktop.html">前往管理台</a>）' : '')
+            (role === 'admin' ? '（<a href="/portal.html">前往管理台</a>）' : '')
           setBusy(false)
         } catch {
           msg.textContent = '进入工作台失败：网络错误'

web/plugins.html

@@ -1,11 +0,0 @@
-<!doctype html>
-<html lang="zh-CN">
-<head>
-<meta charset="utf-8" />
-<meta http-equiv="refresh" content="0;url=/portal.html#/plugins" />
-<title>跳转中…</title>
-</head>
-<body>
-<script>location.replace('/portal.html#/plugins')</script>
-</body>
-</html>

web/skills.html

@@ -1,11 +0,0 @@
-<!doctype html>
-<html lang="zh-CN">
-<head>
-<meta charset="utf-8" />
-<meta http-equiv="refresh" content="0;url=/portal.html#/skills" />
-<title>跳转中…</title>
-</head>
-<body>
-<script>location.replace('/portal.html#/skills')</script>
-</body>
-</html>