kandev/docs/plans/parent-child-task-stop/task-01-execution-stop-semantics.md

id, title, status, wave, depends_on, plan, spec

id	title	status	wave	depends_on	plan	spec
01-execution-stop-semantics	Execution stop outcomes	done	1		plan.md	../../specs/tasks/parent-child-task-stop.md

Task 01: Execution stop outcomes

Acceptance

• A detailed per-session stop primitive distinguishes accepted cancellation, natural terminal/absent execution, and genuine lookup/persistence failure.
• Only lifecycle.ErrNoExecutionForSession counts as natural absence. Other lookup errors and empty-ID/nil are failures.
• The stop-specific state transition reports changed/final state. Natural terminal races do not get overwritten or count as stopped; successful acceptance persists CANCELLED before async teardown.
• State-write failure prevents teardown for that candidate. Runtime teardown is asynchronous and detached from caller cancellation.
• Existing UI, completion, Office/tree/workspace, and handoff stop callers retain supplied reason/force and legacy ErrExecutionNotFound / partial-success behavior.

Verification

cd apps/backend && go test ./internal/orchestrator/executor ./internal/orchestrator

Files Likely Touched

• apps/backend/internal/orchestrator/executor/executor_interaction.go
• apps/backend/internal/orchestrator/executor/executor_interaction_test.go
• apps/backend/internal/orchestrator/executor/executor_mocks_test.go
• apps/backend/internal/orchestrator/service.go
• apps/backend/internal/orchestrator/event_handlers_streaming.go
• apps/backend/internal/orchestrator/event_handlers_streaming_test.go

Dependencies

None.

Inputs

• Spec: What, State and persistence, Failure modes, and Scenarios.
• Existing task-stop seam: Service.StopTask and Executor.StopByTaskID.
• Normal lifecycle absence sentinel: lifecycle.ErrNoExecutionForSession.

Output Contract

Update this task to done, update plan.md, and report per-session outcomes, legacy compatibility, files changed, tests run, blockers, and remaining lifecycle risks.

Completion

• Added a strict per-session outcome with accepted/final-state reporting.
• Added exact execution teardown ownership across coordinator stops, terminal cleanup, launch/recovery races, and durable task-resource cleanup.
• Preserved legacy stop sentinels while exposing exact runtime absence as idempotent; real lookup and persistence failures remain retryable.
• Added an atomic session-owned task-state CAS so clarification/terminal state cannot be overwritten by delayed runtime reconciliation.
• Changed areas: runtime/lifecycle stop contracts, orchestrator executor and recovery paths, task cleanup jobs, MCP clarification state, and focused E2E coverage.
• Tests run: make fmt, make typecheck, make test, make lint, scoped Go race suites, and the sidebar-clarification and Office-onboarding Playwright specs against production builds.
• Blockers: none.
• Remaining lifecycle risks: none known; session-scoped lookup absence remains retryable until an exact execution identity is available.