Add ctx.ScheduleNewWorkflow for detached workflows

[acroca]

Ref: dapr/dapr#9261

Summary

Adds first-class support for spawning a fully decoupled workflow from within another workflow, replacing the prior pattern of wrapping a WorkflowClient.ScheduleNewWorkflow call inside an activity.

What this does

• New orchestrator-context method: WorkflowContext.ScheduleNewWorkflow(workflow, opts...) (api.InstanceID, error). Returns the new instance ID synchronously — there is no awaitable Task because the spawned workflow is fire-and-forget.
• Wrapper-layer mirror in workflow/.
• Runtime applier branch that, on CreateDetachedWorkflowAction:
  • Appends a single DetachedWorkflowInstanceCreatedEvent to the caller's history (event id == action id).
  • Emits an ExecutionStartedEvent for the new instance with ParentInstance == nil, propagating Name, Input, Tags, ScheduledStartTimestamp, ParentTraceContext (action's, with fallback to current trace context), and ExecutionId (mints a UUID when absent, matching the client API).
  • Mints a fresh, target-only routing envelope on the spawned StartEvent (no SourceAppID back-reference) so the new workflow looks like a freshly client-scheduled top-level workflow.
• Version is intentionally NOT propagated to the spawned StartEvent, matching the existing CreateChildWorkflow precedent.

[Copilot]

Pull request overview

This PR adds first-class “detached workflow” scheduling from inside an orchestrator via WorkflowContext.ScheduleNewWorkflow, enabling fire-and-forget spawning without parent linkage (so completion/failure does not flow back to the caller).

Changes:

• Introduces task.WorkflowContext.ScheduleNewWorkflow (plus workflow/ wrapper) with deterministic default instance ID generation when no instance ID is provided.
• Extends the runtime applier to handle CreateDetachedWorkflowAction by recording a DetachedWorkflowInstanceCreated event in the caller and emitting an ExecutionStarted event for the spawned instance with no parent linkage and target-only routing.
• Adds unit/integration tests covering detached workflow scheduling, determinism across replay, routing behavior, and execution ID minting.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
workflow/workflow.go	Adds wrapper-level ScheduleNewWorkflow and detached workflow option helpers.
task/orchestrator.go	Implements ScheduleNewWorkflow orchestration API, options, and replay retirement logic.
backend/runtimestate/applier.go	Applies CreateDetachedWorkflowAction by recording caller history + emitting spawned start message with no parent linkage.
tests/runtimestate_test.go	Adds applier-focused tests for detached workflow history/message shaping and routing/execution ID behavior.
tests/orchestrations_test.go	Adds end-to-end tests for detached workflow lifecycle, default IDs, non-propagation of failure, and replay determinism.
task/detached_workflow_test.go	Adds orchestrator-context unit tests for emitted actions/options and replay retirement behavior.
api/protos/orchestrator_actions.pb.go	Updates generated protos to include CreateDetachedWorkflowAction and wiring in WorkflowAction.

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[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 1 comment.