fix(sessions): terminalize session on workflow completion

DefaultSessionReducer skipped WorkflowCompletedEvent to avoid terminalizing on freestyle planning's mid-session completion, but that left execution/normal completions stuck ACTIVE forever — headless watchers and approval loops never saw a terminal state. Add workflowId to WorkflowCompletedEvent (defaulted for replay compat), pass graph.id at all completeWorkflow sites, and terminalize to COMPLETED unless it's the freestyle_planning handoff. Correct stale tests that pinned the ACTIVE-forever behavior.

core/kernel/src/main/kotlin/com/correx/core/kernel/orchestration/DefaultSessionOrchestrator.kt

@@ -168,7 +168,7 @@ class DefaultSessionOrchestrator(
             }
 
             is TransitionDecision.Stay -> if (isTerminal(enriched.graph, enriched.currentStageId)) {
-                completeWorkflow(enriched.sessionId, enriched.currentStageId, enriched.stageCount)
+                completeWorkflow(enriched.sessionId, enriched.currentStageId, enriched.stageCount, enriched.graph.id)
             } else {
                 // No outgoing edge matched: the stage finished but produced nothing that satisfies a
                 // transition (e.g. the analyst never emitted a validated `analysis`). Treat it as a
@@ -335,7 +335,7 @@ class DefaultSessionOrchestrator(
         if (isTerminal(ctx.graph, nextStageId)) {
             // Terminal stage is a sentinel — not executed, so don't count it.
             return StepResult.Terminal(
-                completeWorkflow(ctx.sessionId, nextStageId, ctx.stageCount),
+                completeWorkflow(ctx.sessionId, nextStageId, ctx.stageCount, ctx.graph.id),
             )
         }
 

core/kernel/src/main/kotlin/com/correx/core/kernel/orchestration/ReplayOrchestrator.kt

@@ -117,7 +117,7 @@ class ReplayOrchestrator(
                 val nextStageId = decision.to
 
                 if (isTerminal(ctx.graph, nextStageId)) {
-                    return completeWorkflow(ctx.sessionId, nextStageId, ctx.stageCount)
+                    return completeWorkflow(ctx.sessionId, nextStageId, ctx.stageCount, ctx.graph.id)
                 }
 
                 when (val result = enterStage(ctx, nextStageId, session)) {
@@ -131,7 +131,7 @@ class ReplayOrchestrator(
             }
 
             is TransitionDecision.Stay -> if (isTerminal(ctx.graph, ctx.currentStageId)) {
-                completeWorkflow(ctx.sessionId, ctx.currentStageId, ctx.stageCount)
+                completeWorkflow(ctx.sessionId, ctx.currentStageId, ctx.stageCount, ctx.graph.id)
             } else {
                 step(ctx)
             }

core/kernel/src/main/kotlin/com/correx/core/kernel/orchestration/SessionOrchestrator.kt

@@ -2065,13 +2065,14 @@ abstract class SessionOrchestrator(
         sessionId: SessionId,
         terminalStageId: StageId,
         stageCount: Int,
+        workflowId: String,
     ): WorkflowResult.Completed {
         log.debug(
             "[Orchestrator] COMPLETED session={} terminalStage={} stages={}",
             sessionId.value, terminalStageId.value, stageCount,
         )
         correlateCritiqueOutcomes(sessionId)
-        emit(sessionId, WorkflowCompletedEvent(sessionId, terminalStageId, stageCount))
+        emit(sessionId, WorkflowCompletedEvent(sessionId, terminalStageId, stageCount, workflowId))
         cancellations.remove(sessionId)
         return WorkflowResult.Completed(sessionId, terminalStageId)
     }