refactor(sdk): remove unreleased project toolchain

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

@@ -37,7 +37,7 @@ Every later turn creates another Task. Its producer resources cover only that ac
 
 Opening a child session in a human-facing adapter reads its persisted transcript and does not resume an Agent merely to display it. Human input starts or joins the same Task-backed activation used by parent input through the continuation manager. A human-started Task retains the exact currently loaded parent Agent as its notification target, and `task_output` remains the single result path. The existing completion listener injects at most one unsolicited notice while the Task is unreported; `kill`, a terminal read, or a terminal wait may mark it reported and suppress that notice. Human interaction is therefore permitted only while that parent instance remains live. A user-owned conversation that may outlive the parent and explicitly merge a conclusion back belongs to [interactive side sessions](../../proposed/feature/2026-07-08-interactive-side-sessions.md), not this Task-owned lifecycle.
 
-`TaskService.start()` rejects producers when no Task control surface is attached. A human-facing adapter that accepts child input must therefore attach a Task control surface, or run in a deployment that loads `@deepseek-ai/dsh-tool-tasks`; loading the Task service alone is insufficient. SDK-generated spawn and fork compositions mount `@deepseek-ai/dsh-tasks-local` and `@deepseek-ai/dsh-tool-tasks` with the subagent tools. This dependency is the cost of using the same Task result, cancellation, and notification path for parent- and human-started activations.
+`TaskService.start()` rejects producers when no Task control surface is attached. A human-facing adapter that accepts child input must therefore attach a Task control surface, or run in a deployment that loads `@deepseek-ai/dsh-tool-tasks`; loading the Task service alone is insufficient. This dependency is the cost of using the same Task result, cancellation, and notification path for parent- and human-started activations.
 
 Cancellation always targets the whole current activation. If human and parent messages have joined one turn, either caller's cancellation aborts that turn, disposes its run, and settles its Task as `killed`; the messages do not have independent results or cancellation rights. `followup()` requires the caller's signal, and abort while live steering awaits request admission aborts the activation-owned controller so the provider discards the pending message and the call settles only after the child reaches quiescence. Independent cancellation requires a later message to start a separate turn instead of steering the current one.
 
@@ -112,7 +112,7 @@ Task records and active-run associations are process-local. Persistence makes th
 - `packages/subagent/subagent-inprocess/tests/subagent-inprocess.spec.ts` pins the continuable durability boundary: an absent or detached flush listener and a permanent listener failure reject with `DURABILITY_FAILED`, a transient loop-checkpoint failure can succeed on the final confirmation, cancellation owns either final-checkpoint outcome, resume also confirms durability, and foreground runs remain best-effort. `packages/subagent/subagent/tests/continuation.spec.ts` drives the real stack (agent loop, JSONL persistence, spawn/fork providers, Task service, and `ctx.subagents`) keylessly: initial and resumed activations create fresh Tasks and dispose their runs before terminal; the descriptor event is pre-turn, model-hidden, versioned, durable under the service-allocated child id, and survives blocked or throwing initial prompt admission; cancellation, steering, cold follow-up, authorization, ownership conflicts, and resume races retain the contracts described above.
 - `packages/subagent/tool-subagent-control/tests/tool-subagent-control.spec.ts` pins the `send_message` schema, coordinator attribution, both route renderings, the not-delivered failure, the no-agent rejection, and HMR disposal.
 - `packages/subagent/tool-subagent/tests/tool-subagent.spec.ts` covers the configured background route: continuable mode requires a resumable provider and returns both ids without requiring `send_message`, while one-shot mode keeps the plain Task acknowledgement even when the provider can resume.
-- `packages/scaffold/helper/tests/project.spec.ts` pins the Task service and model-facing Task controls in generated spawn and fork compositions.
+- `packages/subagent/tool-subagent/tests/tool-subagent.spec.ts` pins Task service integration and the model-facing Task controls.
 - The keyless ACP snapshot scenario `subagent-continuable` (examples/acp-agent) pins the model-visible transcript: the two-id acknowledgement, a final durability-confirmation failure rendered through `task_output` without unconfirmed child output, and a `send_message` follow-up whose started Task fails with the id unavailable.
 
 ## Consequences