feat(HEL-560): 数据中枢接管数据源/模型池/会员，注册改一次性邀请码

主站
- 新增 m0006 invite_codes 迁移；注册强制邀请码（首个管理员除外），消码与建号
  同一事务，并发提交只有一个能成功
- 新增 /api/hub-admin/* 服务端点（共享 HUB_ADMIN_TOKEN，先于鉴权校验），供数据
  中枢桥接读写会话/密码/模型池/会员/邀请码，并提供供应商模型列表拉取
- 前端：注册表单加邀请码（桌面 login、index.html、移动端）；「系统管理」改为
  「数据中枢」入口指向 8766，原模型池与会员管理分区移除，仅留「行情管理」；
  随之清理陈旧 CSS

数据中枢
- 取消独立账号：删除 hub_admin/hub_sessions 与登录、改密、锁定逻辑，改为校验
  主站 xiaobai_session，仅管理员可进，CSRF 由会话派生，危险操作二次确认走主站
- 控制台新增数据源凭证可编辑区（原有内容一项不删）、供应商制模型池（自动拉取
  /models，失败退回卡内手动录入）、会员管理与邀请码页
- 日夜双主题：颜色收敛为同名 token 换值，SVG 改用 inline style 以吃到变量

自测
- 主站 verify_baseline 通过（498 项）；数据中枢 235 项通过
- tools/verify_datahub_console.py 端到端跑通两服务真实对话；
  tools/verify_datahub_console_ui.py 浏览器跑通门禁/凭证/模型池/会员/主题/1030 窄屏

Co-authored-by: multica-agent <github@multica.ai>

frontend/index.html

@@ -73,6 +73,7 @@
         <label class="form-field"><span>账号名</span><input id="authUsername" type="text" minlength="3" maxlength="30" autocomplete="username" required></label>
         <label class="form-field"><span>密码</span><input id="authPassword" type="password" minlength="8" maxlength="128" autocomplete="current-password" required></label>
         <label id="authConfirmField" class="form-field" hidden><span>确认密码</span><input id="authPasswordConfirm" type="password" minlength="8" maxlength="128" autocomplete="new-password"></label>
+        <label id="authInviteField" class="form-field" hidden><span>邀请码</span><input id="authInviteCode" type="text" maxlength="32" autocomplete="off" spellcheck="false" placeholder="XB-XXXX-XXXX-XXXX"></label>
         <p id="authError" class="auth-error" hidden></p>
         <button id="authSubmitButton" class="button primary" type="submit">登录</button>
       </form>
@@ -156,7 +157,8 @@
         </div>
         <button id="refreshButton" class="button command-button" type="button" title="刷新"><i data-lucide="refresh-cw"></i><span>刷新</span></button>
         <button id="syncButton" class="button primary command-button" type="button" title="后台刷新" hidden><i data-lucide="cloud-download"></i><span>后台刷新</span></button>
-        <button id="settingsButton" class="button command-button" type="button" title="系统管理" hidden><i data-lucide="settings-2"></i><span>系统管理</span></button>
+        <button id="marketAdminButton" class="button command-button" type="button" title="行情管理" hidden><i data-lucide="settings-2"></i><span>行情管理</span></button>
+        <button id="settingsButton" class="button command-button" type="button" title="数据中枢" hidden><i data-lucide="database"></i><span>数据中枢</span></button>
         <div class="account-menu-shell">
           <div id="accountRoleBadges" class="account-role-badges" aria-label="账号身份">
             <span id="accountAdminBadge" class="account-role-badge admin-role-badge" title="管理员" hidden><i data-lucide="shield-check"></i><span>管理员</span></span>
@@ -592,18 +594,11 @@
 
   <dialog id="adminDialog" class="settings-dialog admin-dialog" aria-labelledby="adminDialogTitle">
     <div class="dialog-header">
-      <div><span class="dialog-eyebrow">管理员</span><h2 id="adminDialogTitle">系统配置</h2></div>
+      <div><span class="dialog-eyebrow">管理员</span><h2 id="adminDialogTitle">行情管理</h2></div>
       <button id="closeAdminDialog" class="icon-button" type="button" aria-label="关闭" title="关闭"><i data-lucide="x"></i></button>
     </div>
     <div id="adminConnectionStatus" class="connection-status" aria-live="polite">正在读取系统状态</div>
-    <div class="admin-section-picker">
-      <label for="adminSectionSelect">管理项目</label>
-      <select id="adminSectionSelect">
-        <option value="market">行情管理</option>
-        <option value="models">模型池</option>
-        <option value="members">会员管理</option>
-      </select>
-    </div>
+    <p class="form-hint">模型池、会员与邀请码已统一在数据中枢管理，点击顶栏「数据中枢」进入。</p>
     <div class="admin-panel" data-admin-panel="market">
       <form id="systemMarketForm" class="settings-section">
         <div class="settings-section-heading"><h3>公共行情</h3><span id="systemDataStatus">待检查</span></div>
@@ -624,28 +619,6 @@
         <div class="dialog-actions"><button id="backfillButton" class="button" type="button">开始回补</button></div>
       </section>
     </div>
-    <div class="admin-panel" data-admin-panel="models" hidden>
-      <form id="systemModelsForm" class="settings-section">
-        <div class="settings-section-heading"><h3>平台模型池</h3><span>会员共享</span></div>
-        <div class="model-role-selectors">
-          <label class="form-field"><span>主模型</span><select id="platformPrimaryModelSelect"></select></label>
-          <label class="form-field"><span>辅助模型</span><select id="platformFallbackModelSelect"><option value="">不启用辅助模型</option></select></label>
-        </div>
-        <div id="modelPoolList" class="model-pool-list"></div>
-        <div class="dialog-actions admin-inline-actions"><button id="addPlatformModel" class="button" type="button"><i data-lucide="plus"></i>添加模型</button><button class="button primary" type="submit">保存模型池</button></div>
-      </form>
-    </div>
-    <div class="admin-panel" data-admin-panel="members" hidden>
-      <form id="membershipSettingsForm" class="settings-section membership-limit-form">
-        <div class="settings-section-heading"><h3>会员调用额度</h3><span>每日自动重置</span></div>
-        <label class="form-field compact-number-field"><span>会员每日智能分析上限</span><input id="memberDailyLimit" type="number" min="1" max="1000" value="50"></label>
-        <div class="dialog-actions"><button class="button primary" type="submit">保存调用额度</button></div>
-      </form>
-      <section class="settings-section">
-        <div class="settings-section-heading"><h3>会员账号</h3><span>手动开通与续期</span></div>
-        <div id="adminUsersList" class="admin-users-list"></div>
-      </section>
-    </div>
   </dialog>
 
   <div id="loadingOverlay" class="loading-overlay" hidden>