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>

tests/e2e/app-shell.spec.js

@@ -632,6 +632,7 @@ test("admin shell opens every primary workspace and global search", async ({ pag
   await expect(page.locator("#authGate")).toBeHidden();
   await openHeaderCommandMenu(page);
   await expect(page.locator("#settingsButton")).toBeVisible();
+  await expect(page.locator("#marketAdminButton")).toBeVisible();
   await expect(page.locator("#syncButton")).toBeVisible();
   await page.keyboard.press("Escape");
   await page.locator("#alertButton").click();
@@ -1753,6 +1754,7 @@ test("regular account cannot see admin controls and member features are gated",
   await mockApplication(page, session("user", false));
   await page.goto("/index.html");
   await expect(page.locator("#settingsButton")).toBeHidden();
+  await expect(page.locator("#marketAdminButton")).toBeHidden();
   await expect(page.locator("#syncButton")).toBeHidden();
   await expect(page.locator("#accountVipLabel")).toHaveText("非会员");
   await page.locator('[data-view="screenerView"]').first().click();
@@ -3332,9 +3334,9 @@ test("global dialogs share the stage 18 geometry without changing account or adm
   await page.locator("#closeSettingsDialog").click();
 
   await openHeaderCommandMenu(page);
-  await page.locator("#settingsButton").click();
+  await page.locator("#marketAdminButton").click();
   await expect(page.locator("#adminDialog")).toHaveAttribute("aria-labelledby", "adminDialogTitle");
-  await expect(page.locator("#adminSectionSelect")).toBeVisible();
+  await expect(page.locator("#systemMarketForm")).toBeVisible();
   const adminBox = await page.locator("#adminDialog").boundingBox();
   expect(adminBox.width).toBeLessThanOrEqual(902);
   expect(Math.abs(adminBox.x + adminBox.width / 2 - 720)).toBeLessThanOrEqual(2);
@@ -3510,7 +3512,7 @@ test("B-199 screener review and account surfaces fit day night viewports", async
   await page.locator("#closeSettingsDialog").click();
 
   await openHeaderCommandMenu(page);
-  await page.locator("#settingsButton").click();
+  await page.locator("#marketAdminButton").click();
   await expect(page.locator("#adminDialog")).toBeVisible();
   await shot("admin-1600-day");
   await page.locator("#closeAdminDialog").click();
@@ -3609,6 +3611,7 @@ test("desktop header keeps refresh, admin commands and account identity visible"
     await expect(page.locator("#refreshButton")).toBeVisible();
     await expect(page.locator("#syncButton")).toBeVisible();
     await expect(page.locator("#settingsButton")).toBeVisible();
+    await expect(page.locator("#marketAdminButton")).toBeVisible();
     await expect(page.locator("#accountAdminBadge")).toBeVisible();
     await expect(page.locator("#accountVipBadge")).toBeVisible();
     await expect(page.locator("#accountButton")).toBeVisible();
@@ -3621,7 +3624,7 @@ test("desktop header keeps refresh, admin commands and account identity visible"
     expect(geometry.nameFits, `${viewport.width} account name truncated`).toBe(true);
     await page.locator("#refreshButton").click();
     await expect(page.locator("#loadingOverlay")).toBeHidden();
-    await page.locator("#settingsButton").click();
+    await page.locator("#marketAdminButton").click();
     await expect(page.locator("#adminDialog")).toBeVisible();
     await page.locator("#closeAdminDialog").click();
     await page.locator("#accountButton").click();
@@ -3668,6 +3671,7 @@ test("desktop header keeps refresh, admin commands and account identity visible"
   await expect(page.locator("#refreshButton")).toBeVisible();
   await expect(page.locator("#syncButton")).toBeHidden();
   await expect(page.locator("#settingsButton")).toBeHidden();
+  await expect(page.locator("#marketAdminButton")).toBeHidden();
   await expect(page.locator("#accountAdminBadge")).toBeHidden();
   await expect(page.locator("#accountVipBadge")).toBeVisible();
   await expect(page.locator("#accountName")).toHaveText("normal_user");