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/ChatPanel.test.tsx

@@ -4,7 +4,7 @@ import { createElement } from "react";
 
 import type { Conversation, Model } from "../../../src/shared/api";
 
-import { ChatPanel } from "../../../src/web/consoles/workbench/components/chat/ChatPanel";
+import { ChatPanel } from "../../../src/web/features/chat/ChatPanel";
 import { installFetchMock, jsonResponse, renderWithProviders } from "../test-utils";
 
 const PROJECT_ID = "proj-1";