refactor(packages): dissolve ui/ and rename sdk/ to scaffold/

git mv per the regrouping RFC: the five human-collaboration seams and
tui join packages/interaction/, app-boot becomes packages/boot/, and
jsonrpc joins the renamed scaffold/ (formerly sdk/) as its server half
beside client/protocol/create-sdk/helper/scripts/telemetry, whose
folders drop the legacy sdk- prefix. Three new group README triplets
replace the ui/ and sdk/ ones; tsconfig references/paths/globs,
knip keys, vitest globs, gate scripts, catalogs, docs, and the
lockfile follow. Adds the four settled FIXME rename markers
(dsh-sdk-server, dsh-sdk-telemetry, dsh-sdk-helper, dsh-sdk-scripts).

The scaffold folders diverge from their npm names until those renames
land, so tsconfig.base.json maps the three affected names explicitly
beside the group wildcard. Also repairs two pre-existing stale-path
classes the strengthened sweep surfaced: docs/web-styling.md's retired
web-ui host package and type-model spec fixture-literal joins.

app-boot's three Loader-composition specs time out at the default 5s
under full-suite parallel load on this filesystem (pre-existing;
pass isolated with --testTimeout=30000); interaction/scaffold/boot
suites otherwise green (687 passed).

.agents/notes/implemented/feature/2026-07-21-continuable-background-subagents.zh.md

@@ -112,7 +112,7 @@ Task 记录和活跃 run 关联都位于进程内。持久化使 child 会话可
 - `packages/subagent/subagent-inprocess/tests/subagent-inprocess.spec.ts` 固定可继续执行的持久性边界：缺少 flush 监听器、flush 监听器已脱离或监听器持续失败时，均会以 `DURABILITY_FAILED` 拒绝；循环检查点的瞬时失败可在最终确认成功后继续完成，发生取消时最终检查点无论成功还是失败都由取消优先决定结果，resume 同样会确认持久性，而前台运行仍采用尽力而为策略。`packages/subagent/subagent/tests/continuation.spec.ts` 以无密钥方式驱动真实栈（agent loop、JSONL 持久化、spawn／fork 提供方、Task 服务和 `ctx.subagents`）：初始及恢复后的激活都会创建新 Task，并在进入终态前 dispose 各自的 run；描述符事件位于轮次前、对模型隐藏、带版本、在服务分配的 child id 下持久化，并在初始 prompt admission 阻止请求或抛出异常时仍保留；取消、steering、cold follow-up、授权、所有权冲突与 resume 竞态保留上述契约。
 - `packages/subagent/tool-subagent-control/tests/tool-subagent-control.spec.ts` 固定 `send_message` 的 schema、coordinator 来源标记、两种路由渲染、未送达失败、无 agent 时的拒绝，以及 HMR（热模块替换）dispose。
 - `packages/subagent/tool-subagent/tests/tool-subagent.spec.ts` 覆盖配置的后台路由：可继续模式要求提供方可恢复，并在不要求 `send_message` 的情况下返回两个 id；即使提供方可以恢复，一次性模式仍保持普通的 Task 确认消息。
-- `packages/sdk/helper/tests/project.spec.ts` 固定生成的 spawn 与 fork 组合中的 Task 服务及面向模型的 Task 控制工具。
+- `packages/scaffold/helper/tests/project.spec.ts` 固定生成的 spawn 与 fork 组合中的 Task 服务及面向模型的 Task 控制工具。
 - 无密钥 ACP 快照场景 `subagent-continuable`（examples/acp-agent）固定模型可见的 transcript：双 id 确认消息、最终持久性确认失败（该失败通过 `task_output` 呈现，且不包含未经确认的 child 输出），以及一次 `send_message` 后续操作——其已启动的 Task 会带着「id 不可用」失败。
 
 ## 影响