refactor(web): 前端目录重构 — consoles/pages → layouts/features + shared

- consoles/admin/ → layouts/admin-layout/
- consoles/workbench/ → layouts/workbench-layout/ + features/chat/
- pages/ → features/ (dashboard, models, projects, not-found)
- components/ → shared/components/
- hooks/ → shared/hooks/
- utils/ → shared/utils/
- 更新所有 import 路径 (src/web/ + tests/web/)
- 更新开发文档 (README.md, frontend.md, architecture.md)

tests/web/components/Sidebar/index.test.tsx

@@ -3,8 +3,8 @@ import { describe, expect, test } from "bun:test";
 import { createElement } from "react";
 import { useLocation } from "react-router";
 
-import { Sidebar } from "../../../../src/web/components/Sidebar";
-import { ADMIN_MENU_ITEMS } from "../../../../src/web/consoles/admin/menu";
+import { ADMIN_MENU_ITEMS } from "../../../../src/web/layouts/admin-layout/menu";
+import { Sidebar } from "../../../../src/web/shared/components/Sidebar";
 import { renderWithProviders } from "../../test-utils";
 
 function LocationProbe() {