docs: require task worktrees for distributed development

docs/reference/dev-environment.md

@@ -25,6 +25,8 @@ tran D601:/home/ubuntu/workspace/unidesk-dev git remote -v
 
 若路径、分支或 remote 不符合预期，先修正 fixed workspace，再继续。`/home/ubuntu/cq-deploy`、Code Queue pod 内 `/root/unidesk`/`/app`、D601 上的 `/root/unidesk` 和 `/tmp/unidesk-*` 只作为部署副本、运行副本或临时实验面；运行面热修可以直接作用在 pod/容器，但必须随后把持久化修复提交到 Git remote，并在 fixed workspace 中复验。
 
+固定 workspace 只作为 source truth 预检、fetch、worktree 管理和最终同步入口。实际开发、文档修改、测试补丁和 PR 准备应在固定 repo 下的独立 worktree 中完成，例如 `/home/ubuntu/workspace/unidesk-dev/.worktree/<task>`；该 worktree 必须从最新 `origin/master` 创建，使用任务专属分支或按当前 master-only 规则完成提交，结束前用 `git status` 确认只包含本任务文件。不要把 `/home/ubuntu/workspace/unidesk-dev` 根目录当作并行任务 scratch 区，也不要复用其他任务遗留 worktree。
+
 Master server 不作为 UniDesk 重型验证机。仓库级 check、Playwright/browser smoke、镜像构建、Rust/Go 编译和 Code Queue runner 实测必须放到 D601、CI runner 或其他获批执行面；master server 只做轻量源码编辑、Git 操作、状态观察和受控调度。
 
 ## Public Dev Frontend Port
@@ -106,7 +108,7 @@ The persistent dev environment follows the shared Git-backed deployment hygiene
 
 Use this sequence for backend-core Rust and frontend dev work:
 
-1. Develop in the current `master` worktree and keep unrelated parallel changes separated with `git status`/`git diff`.
+1. Preflight the fixed workspace, then develop in a task-scoped `.worktree/<task>` created from the latest `origin/master`; keep unrelated parallel changes separated with `git status`/`git diff`.
 2. Run local non-Rust checks on the master server, for example `bun scripts/cli.ts check --files --scripts-typecheck --compose --logs`.
 3. Commit and push the code to `origin master`; `deploy apply --env dev` cannot deploy unpushed local changes.
 4. Update `deploy.json` `environments.dev.services` so `backend-core` and `frontend` point at the pushed commit, then commit and push that manifest update.