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>

config/architecture-inventory.json

@@ -13,7 +13,7 @@
     "api_exact_paths": 56,
     "api_prefixes": 0,
     "api_patterns": 11,
-    "database_tables": 37,
+    "database_tables": 38,
     "frontend_page_fragments": 12
   },
   "pages": [
@@ -193,6 +193,7 @@
     "heaven_readings",
     "job_runs",
     "account_switch_grants",
+    "invite_codes",
     "schema_migrations"
   ],
   "background_job_methods": [
@@ -453,8 +454,8 @@
   "code_hotspots": [
     {
       "path": "frontend/pages/heaven/foundation.css",
-      "bytes": 182616,
-      "lines": 11494
+      "bytes": 182527,
+      "lines": 11488
     },
     {
       "path": "frontend/pages/screener/foundation.css",
@@ -478,8 +479,8 @@
     },
     {
       "path": "frontend/index.html",
-      "bytes": 48403,
-      "lines": 665
+      "bytes": 46900,
+      "lines": 638
     },
     {
       "path": "backend/data/providers/tushare_industries.py",
@@ -556,11 +557,6 @@
       "bytes": 14942,
       "lines": 235
     },
-    {
-      "path": "frontend/shared/admin.js",
-      "bytes": 14836,
-      "lines": 283
-    },
     {
       "path": "backend/features/screener/data_sync.py",
       "bytes": 14743,
@@ -573,8 +569,8 @@
     },
     {
       "path": "frontend/shared/session.js",
-      "bytes": 13219,
-      "lines": 289
+      "bytes": 13633,
+      "lines": 296
     },
     {
       "path": "backend/features/market/insights_auction_data.py",
@@ -583,8 +579,8 @@
     },
     {
       "path": "backend/features/system/service.py",
-      "bytes": 12180,
-      "lines": 265
+      "bytes": 12242,
+      "lines": 266
     },
     {
       "path": "backend/features/market/insights_auction.py",
@@ -651,16 +647,16 @@
       "bytes": 6547,
       "lines": 220
     },
+    {
+      "path": "backend/application.py",
+      "bytes": 6500,
+      "lines": 164
+    },
     {
       "path": "frontend/pages/sentiment/page.html",
       "bytes": 6488,
       "lines": 81
     },
-    {
-      "path": "backend/application.py",
-      "bytes": 6399,
-      "lines": 161
-    },
     {
       "path": "frontend/pages/market/stock-detail.js",
       "bytes": 6325,
@@ -701,6 +697,11 @@
       "bytes": 5350,
       "lines": 74
     },
+    {
+      "path": "backend/http/dispatch.py",
+      "bytes": 5281,
+      "lines": 139
+    },
     {
       "path": "frontend/shared/feedback.js",
       "bytes": 5157,
@@ -721,6 +722,11 @@
       "bytes": 4406,
       "lines": 124
     },
+    {
+      "path": "frontend/shared/admin.js",
+      "bytes": 4376,
+      "lines": 107
+    },
     {
       "path": "backend/features/market/routes.py",
       "bytes": 4276,
@@ -736,11 +742,6 @@
       "bytes": 4242,
       "lines": 129
     },
-    {
-      "path": "backend/http/dispatch.py",
-      "bytes": 4196,
-      "lines": 117
-    },
     {
       "path": "frontend/shared/table.js",
       "bytes": 3790,
@@ -783,8 +784,8 @@
     },
     {
       "path": "backend/features/accounts/application.py",
-      "bytes": 2514,
-      "lines": 63
+      "bytes": 2597,
+      "lines": 69
     },
     {
       "path": "backend/jobs/service.py",