Refactor web UI: feature-first structure, tokenized styles, modern blue theme.

Structure
- pages/ -> features/<domain>/{Page, components, hooks, lib}; 95 files moved,
  333 imports rewritten, verified with tsc.
- services/api.ts -> services/api/<domain>.ts (250 exports preserved),
  types.ts -> types/<domain>.ts, i18n zh/en -> locales/<lang>/<namespace>.ts
  (2696 messages deep-equal before/after).
- ESLint rule: shared layers must not import features/.

Styles
- index.css (16k lines) split losslessly into styles/{base,layout,components,
  pages,legacy,theme}; compiled CSS was byte-identical before tokenizing.
- ~930 hard-coded colors replaced by --nx-* tokens (theme/tokens.css); WebCRT
  off-palette colors unified; fixed dark-on-dark text introduced by mapping.
- theme/theme.css: modern blue design language (rounded shapes, gradients,
  unified buttons/fields/tables/modals), form-grid alignment fix, flat nav list
  without tree indent, soft selected state instead of left accent bar.

Docs: WEB.md documents code structure and style rules.
Not touched: the large Biz*/Webcrt/Topology page components (to be split later).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

web/src/i18n/locales/zh/layout.ts

@@ -0,0 +1,26 @@
+const layout = {
+  title: "UME 对接",
+  titleUme: "UME同步",
+  titleNetwork: "网络管理",
+  titleManagedNe: "网元管理",
+  titleCollect: "批量采集",
+  titleWebcrt: "WebCRT",
+  titleTopology: "拓扑管理",
+  titlePortTrafficWall: "流量大屏",
+  titleUsers: "用户管理",
+  titleAudit: "操作审计",
+  titleApiKeys: "API Key",
+  titleSessions: "登录会话",
+  navUme: "UME 对接",
+  netxApi: "netx api",
+  oclawBridge: "oclaw WSS",
+  activeTasks: "活跃任务 {{count}}",
+  activeTasksHint: "打开操作审计 · 任务概览",
+  language: "语言",
+  switchLanguage: "切换语言 / Switch language",
+  moreMenu: "更多",
+  langZh: "中文",
+  langEn: "English",
+};
+
+export default layout;