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/utils/time.test.ts

@@ -6,7 +6,7 @@ import {
   formatRelativeTime,
   isOlderThan,
   subtractHours,
-} from "../../../src/web/utils/time";
+} from "../../../src/web/shared/utils/time";
 
 describe("subtractHours", () => {
   test("正常扣减小时", () => {