fix(kernel): complete artifact lifecycle and fix transition artifact state lookup

Two issues causing "no transition condition matched":

1. emitToolArtifacts only emitted ArtifactCreatedEvent; the artifact_validated
   transition condition requires VALIDATED phase, which needs the full lifecycle
   (Created → Validating → Validated). Tool success is sufficient grounds for
   auto-validation, so emit all three events.

2. DefaultSessionOrchestrator was building stageArtifacts from LiveArtifactRepository
   which uses a hot async subscription — cache was always empty at lookup time.
   Now reads ArtifactValidatedEvents directly from the synchronous EventStore.read().

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

@@ -2,6 +2,10 @@ package com.correx.core.kernel.orchestration
 
 import com.correx.core.approvals.model.ApprovalDecision
 import com.correx.core.artifactstore.ArtifactStore
+import com.correx.core.artifacts.ArtifactState
+import com.correx.core.events.events.ArtifactValidatedEvent
+import com.correx.core.events.types.ArtifactId
+import com.correx.core.events.types.ArtifactLifecyclePhase
 import org.slf4j.LoggerFactory
 import com.correx.core.events.orchestration.OrchestrationState
 import com.correx.core.events.types.ApprovalRequestId
@@ -67,11 +71,16 @@ class DefaultSessionOrchestrator(
         )
 
         val stageConfig = enriched.graph.stages[enriched.currentStageId]
-        val stageArtifacts = stageConfig?.produces
-            ?.let { slots ->
-                repositories.artifactRepository.getByIds(enriched.sessionId, slots.map { it.name }.toSet())
-            }
-            ?: emptyMap()
+        val targetIds: Set<ArtifactId> = stageConfig?.produces?.map { it.name }?.toSet() ?: emptySet()
+        val stageArtifacts: Map<ArtifactId, ArtifactState> = if (targetIds.isEmpty()) {
+            emptyMap()
+        } else {
+            val validated = repositories.eventStore.read(enriched.sessionId)
+                .mapNotNull { (it.payload as? ArtifactValidatedEvent)?.artifactId }
+                .filter { it in targetIds }
+                .toSet()
+            validated.associateWith { ArtifactState(phase = ArtifactLifecyclePhase.VALIDATED) }
+        }
 
         val decision = resolveTransition(enriched.graph, enriched.sessionId, enriched.currentStageId, stageArtifacts)
         log.debug(

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

@@ -11,6 +11,8 @@ import com.correx.core.context.model.ContextPack
 import com.correx.core.context.model.TokenBudget
 import com.correx.core.events.types.ContextEntryId
 import com.correx.core.events.events.ArtifactCreatedEvent
+import com.correx.core.events.events.ArtifactValidatedEvent
+import com.correx.core.events.events.ArtifactValidatingEvent
 import com.correx.core.events.events.ApprovalDecisionResolvedEvent
 import com.correx.core.events.events.ApprovalRequestedEvent
 import com.correx.core.events.events.EventMetadata
@@ -419,15 +421,9 @@ abstract class SessionOrchestrator(
         stageConfig.produces
             .filter { !it.kind.llmEmitted }
             .forEach { slot ->
-                emit(
-                    sessionId,
-                    ArtifactCreatedEvent(
-                        artifactId = slot.name,
-                        sessionId = sessionId,
-                        stageId = stageId,
-                        schemaVersion = 1,
-                    ),
-                )
+                emit(sessionId, ArtifactCreatedEvent(slot.name, sessionId, stageId, schemaVersion = 1))
+                emit(sessionId, ArtifactValidatingEvent(slot.name, sessionId, stageId))
+                emit(sessionId, ArtifactValidatedEvent(slot.name, sessionId, stageId))
             }
     }