kandev/docs/plans/interrupted-task-indicator/task-01-backend-startup-marker.md

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

id	title	status	wave	depends_on	plan	spec
01-backend-startup-marker	Backend startup interruption marker	done	1		plan.md	../../specs/tasks/requirements/interrupted-task-indicator.md

Task 01: Backend startup interruption marker

Acceptance

• models.MetaKeyInterruptedAt = "interrupted_at" exists in the task metadata key block.
• reconcileOneSessionOnStartup writes interrupted_at (RFC 3339 UTC now) onto the owning task when previousState is STARTING or RUNNING and the task exists and is not archived.
• Sessions that were WAITING_FOR_INPUT, IDLE, CREATED, COMPLETED, CANCELLED, or FAILED at startup do not receive the marker.
• A failed marker write logs a warning and does not abort reconciliation.
• The sessionExecutorStore interface exposes SetTaskMetadataKey and RemoveTaskMetadataKey (both already implemented by the concrete repository).

Verification

cd apps/backend && go test ./internal/orchestrator/... -run 'ReconcileSessionsOnStartup'
cd apps/backend && go build ./...

Files likely touched

• apps/backend/internal/task/models/models.go — MetaKeyInterruptedAt.
• apps/backend/internal/orchestrator/service.go — sessionExecutorStore interface + reconcileOneSessionOnStartup active-branch write.
• apps/backend/internal/orchestrator/task_operations_test.go, apps/backend/internal/orchestrator/reconcile_restart_test.go — marker assertions for RUNNING/STARTING vs WAITING_FOR_INPUT vs archived.

Dependencies

None.

Inputs

• Spec: What, Data model, State machine (unmarked → marked), Failure modes.
• Plan: Backend > Marker key and detection.
• Existing pattern: the task IN_PROGRESS → REVIEW guard write in the same function (taskArchived + UpdateTaskStateIfCurrentIn).

Risks

• Marking a task whose taskID is empty, or an archive committing between a guard read and the metadata write — the marker write must be archive-atomic (SetTaskMetadataKeyIfNotArchived, archived_at IS NULL in the same statement), so a concurrent archive can never leave a stale marker.
• Test wrappers embedding sessionExecutorStore compile unchanged because they embed the interface.

Output contract

Report the marker key, where the write sits in the reconciliation flow, the exact tests added (including the negative cases), commands and results, then mark this task done and update its checkbox in plan.md.