feat(events): RefinementIterationEvent + orchestration state counter

core/events/src/main/kotlin/com/correx/core/events/events/RefinementEvents.kt

@@ -0,0 +1,19 @@
+package com.correx.core.events.events
+
+import com.correx.core.events.types.SessionId
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * Records one pass through a refinement cycle (e.g. implementer→reviewer→implementer).
+ * [cycleKey] identifies the loop (e.g. "implement->review"). [iteration] is 1-based.
+ * Recorded so the runtime refinement guard is replay-deterministic (invariant #8).
+ */
+@Serializable
+@SerialName("RefinementIteration")
+data class RefinementIterationEvent(
+    val sessionId: SessionId,
+    val cycleKey: String,
+    val iteration: Int,
+    val maxIterations: Int,
+) : EventPayload

core/events/src/main/kotlin/com/correx/core/events/orchestration/OrchestrationState.kt

@@ -14,4 +14,5 @@ data class OrchestrationState(
     val pendingApproval: Boolean = false,
     val failureReason: String? = null,
     val retryPolicy: RetryPolicy? = null,
+    val refinementIterations: Map<String, Int> = emptyMap(),
 )

core/events/src/main/kotlin/com/correx/core/events/serialization/Serialization.kt

@@ -23,6 +23,7 @@ import com.correx.core.events.events.ModelLoadedEvent
 import com.correx.core.events.events.ModelUnloadedEvent
 import com.correx.core.events.events.OrchestrationPausedEvent
 import com.correx.core.events.events.OrchestrationResumedEvent
+import com.correx.core.events.events.RefinementIterationEvent
 import com.correx.core.events.events.RetryAttemptedEvent
 import com.correx.core.events.events.RiskAssessedEvent
 import com.correx.core.events.events.StageCompletedEvent
@@ -78,6 +79,7 @@ val eventModule = SerializersModule {
         subclass(WorkflowFailedEvent::class)
         subclass(WorkflowCompletedEvent::class)
         subclass(RetryAttemptedEvent::class)
+        subclass(RefinementIterationEvent::class)
         subclass(RiskAssessedEvent::class)
         subclass(ChatSessionStartedEvent::class)
         subclass(ChatTurnEvent::class)

core/events/src/test/kotlin/com/correx/core/events/serialization/RefinementEventSerializationTest.kt

@@ -0,0 +1,25 @@
+package com.correx.core.events.serialization
+
+import com.correx.core.events.events.EventPayload
+import com.correx.core.events.events.RefinementIterationEvent
+import com.correx.core.events.types.SessionId
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class RefinementEventSerializationTest {
+
+    @Test
+    fun `RefinementIterationEvent round-trips as polymorphic EventPayload`() {
+        val sample: EventPayload = RefinementIterationEvent(
+            sessionId = SessionId("s"),
+            cycleKey = "implement->review",
+            iteration = 2,
+            maxIterations = 3,
+        )
+        val encoded = eventJson.encodeToString(EventPayload.serializer(), sample)
+        assertTrue(encoded.contains("\"type\":\"RefinementIteration\""), "SerialName must be present: $encoded")
+        val decoded = eventJson.decodeFromString(EventPayload.serializer(), encoded)
+        assertEquals(sample, decoded)
+    }
+}