Struct StreamingExecution 

pub struct StreamingExecution {
    pub events: UnboundedReceiver<FlowExecutionEvent>,
    pub exited: Arc<Notify>,
    pub enforcement_summaries: Arc<Mutex<HashMap<String, EnforcementSummaryWire>>>,
    pub step_audit_records: Arc<Mutex<Vec<StepAuditRecord>>>,
    pub runtime_warnings: Arc<Mutex<Vec<RuntimeWarning>>>,
}

§Fase 33.f — Handles returned by server_execute_streaming.

Bundles the [FlowExecutionEvent] receiver with an “exited” signal the consumer can await to confirm the producer task has terminated (e.g. for cancel-safety budgets in tests / metrics).

Fields

events: UnboundedReceiver<FlowExecutionEvent>

exited: Arc<Notify>

Resolves once the producer’s spawn_blocking task exits, for any reason (normal completion, cancellation, or send-failure on a dropped consumer). Pairs with the crate::cancel_token::CancellationFlag the producer observes between emits.

enforcement_summaries: Arc<Mutex<HashMap<String, EnforcementSummaryWire>>>

§Fase 33.x.d — Per-step EnforcementSummary side-channel.

Populated by the async streaming producer (run_streaming_async_path) as each step’s crate::stream_effect_dispatcher::StreamPolicyEnforcer finishes draining. Read by the consumer (execute_sse_handler) when emitting axon.complete so the wire body includes the enforcement summary per step that had a declared <stream:<policy>> effect.

Empty for:

• The legacy synchronous fallback path (run_streaming_legacy_path) — preserves v1.24.0 wire byte-compat for adopter shapes the streaming path defers.
• The async path when no step has a declared effect policy — no enforcer is constructed; no summary to publish.

The lock is tokio::sync::Mutex so the producer can hold it across .await points without risk of deadlock from std::sync::Mutex blocking the executor.

step_audit_records: Arc<Mutex<Vec<StepAuditRecord>>>

§Fase 33.x.f — Per-step audit record side-channel.

Populated by the async streaming producer (run_streaming_async_path) after each step finishes draining: one crate::axonendpoint_replay::StepAuditRecord per IRFlowNode::Step that executed. Read by the SSE handler when emitting axon.complete if a ReplayContext is provided (route has replay: true declared) — the records land in the crate::axonendpoint_replay::AxonendpointReplayEntry::step_audit field so GET /v1/replay/<trace_id> returns the per-step sequence to regulators / auditors.

Empty for:

• The legacy synchronous fallback path (run_streaming_legacy_path) — preserves v1.24.0 wire + replay byte-compat.
• SSE routes WITHOUT replay: true — recording the side-channel costs ~one Mutex push per step regardless of replay binding (cheap), but the entry is never written.

runtime_warnings: Arc<Mutex<Vec<RuntimeWarning>>>

§Fase 33.x.g — Runtime warning side-channel.

Populated synchronously by server_execute_streaming BEFORE spawning the producer when the dispatch falls back to the legacy synchronous path. The W002 warning is recorded with the specific crate::runtime_warnings::FallbackMode tag identifying WHY streaming did not activate (unsupported flow shape / unknown backend / source compilation failed / backend lacks stream()).

Read by the SSE consumer at FlowComplete time + projected onto axon.complete.warnings (wire). Also lands on AxonendpointReplayEntry.runtime_warnings (audit) when the route declares replay: true.

D5 contract: NO silent degradation. Empty Vec on the happy path (the async streaming path activated correctly).