Merge origin/master into worktree/remove-sdk-project-toolchain

# Conflicts:
#	.agents/notes/implemented/architecture/2026-07-10-single-file-executable-sdk-runtime-distribution.i18n.yaml
#	.agents/notes/implemented/architecture/2026-07-10-single-file-executable-sdk-runtime-distribution.md
#	.agents/notes/implemented/feature/2026-07-21-continuable-background-subagents.i18n.yaml
#	.agents/notes/implemented/feature/2026-07-21-continuable-background-subagents.md
#	.agents/notes/implemented/feature/2026-07-21-continuable-background-subagents.zh.md
#	.agents/notes/proposed/architecture/2026-07-15-sdk-project-editing-architecture.i18n.yaml
#	.agents/notes/proposed/architecture/2026-07-15-sdk-project-editing-architecture.md
#	.agents/notes/proposed/feature/2026-07-14-sdk-developer-projects.i18n.yaml
#	.agents/notes/proposed/feature/2026-07-14-sdk-developer-projects.md
#	.agents/notes/proposed/feature/2026-07-14-sdk-developer-projects.zh.md
#	packages/README.i18n.yaml
#	packages/README.md
#	packages/scaffold/create-sdk/README.md
#	packages/scaffold/create-sdk/src/args.ts
#	packages/scaffold/scripts/src/args.ts
#	packages/sdk/README.i18n.yaml
#	scripts/verify-package-readme-model-experience.ts

.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. 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 controller is attached. A human-facing adapter that accepts child input must therefore attach a task controller, 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.
 
@@ -121,7 +121,7 @@ Task records and active-run associations are process-local. Persistence makes th
 - Two callers may still race a stopped child through paths outside the continuation manager. The Agent registry prevents duplicate same-session publication; a losing Task fails and its message is not delivered. A message may also race cancellation, terminal status publication, or run disposal. Admission is not claimed to be atomic or exactly-once; the synchronous process-local association install closes duplicate cold resume through `followup` without a public lifecycle state machine.
 - Driving a continuable child through the ordinary Agent API bypasses its Task association. `ctx.subagents` rejects that live child as an ownership conflict; adapters must display persisted transcripts without loading an Agent and submit human input through `SubagentService.followup()`.
 - The active-run association coordinates only one runtime. Concurrent resume from multiple processes is not serialized; that deployment requires a persistence-level lease or compare-and-set operation.
-- Human interaction requires the exact parent Agent instance to remain live because owner disposal cancels and removes its Tasks. It also requires an attached Task control surface. Standalone child interaction requires a future separation between Task access ownership and durable notification targeting.
+- Human interaction requires the exact parent Agent instance to remain live because owner disposal cancels and removes its Tasks. It also requires an attached task controller. Standalone child interaction requires a future separation between Task access ownership and durable notification targeting.
 - The background tool returns child and Task ids before child publication and descriptor durability. Startup failure, a failed final durability confirmation, or process exit before the first child flush leaves the Task failed and may leave an unmaterialized or stale child id; by-id control reports missing state as unavailable rather than retroactively changing the tool acknowledgement.
 - Persisting explicit composition fields in the child log makes their lossless-JSON and compatibility contract part of resume. Later support for another composition input requires a deliberate descriptor-version change rather than implicitly persisting merge-extensible `AgentOptions` fields.
 - Task records and active-run associations are process-local even though child sessions are durable. Restart recovers the session, not in-flight work or its Task notification.