feat(server): Task 3.4 — ServerMessage.Narration + DomainEventMapper arm

apps/server/src/main/kotlin/com/correx/apps/server/bridge/DomainEventMapper.kt

@@ -30,6 +30,7 @@ import com.correx.core.events.events.ToolCallAssessedEvent
 import com.correx.core.events.events.ToolInvocationRequestedEvent
 import com.correx.core.events.events.TransitionExecutedEvent
 import com.correx.core.events.events.WorkflowCompletedEvent
+import com.correx.core.events.events.RouterNarrationEvent
 import com.correx.core.events.events.WorkflowFailedEvent
 import com.correx.core.events.risk.RiskAction
 import com.correx.core.events.types.ArtifactId
@@ -205,6 +206,15 @@ suspend fun domainEventToServerMessage(
             sequence = seq,
             sessionSequence = sessionSequence,
         )
+        is RouterNarrationEvent -> ServerMessage.Narration(
+            sessionId = p.sessionId,
+            content = p.content,
+            stageId = p.stageId,
+            latencyMs = p.latencyMs,
+            totalTokens = p.tokensUsed?.totalTokens,
+            sequence = seq,
+            sessionSequence = sessionSequence,
+        )
         is ArtifactCreatedEvent -> ServerMessage.ArtifactCreated(
             sessionId = p.sessionId,
             stageId = p.stageId,

apps/server/src/main/kotlin/com/correx/apps/server/protocol/ServerMessage.kt

@@ -362,6 +362,18 @@ sealed interface ServerMessage {
 
     // -- Router --
 
+    @Serializable
+    @SerialName("router.narration")
+    data class Narration(
+        val sessionId: SessionId,
+        val content: String,
+        val stageId: String? = null,
+        val latencyMs: Long? = null,
+        val totalTokens: Int? = null,
+        override val sequence: Long,
+        override val sessionSequence: Long,
+    ) : ServerMessage, SessionMessage
+
     @Serializable
     @SerialName("router.response")
     data class RouterResponseMessage(

apps/server/src/test/kotlin/com/correx/apps/server/protocol/ServerMessageSerializationTest.kt

@@ -107,6 +107,24 @@ class ServerMessageSerializationTest {
         assert(jsonStr.contains("\"lastSessionSequence\":15")) { "expected lastSessionSequence=15" }
     }
 
+    @Test
+    fun `Narration encodes type content stageId latencyMs and totalTokens`() {
+        val msg = ServerMessage.Narration(
+            sessionId = SessionId("sess-1"),
+            content = "moving on",
+            stageId = "validate",
+            latencyMs = 2000,
+            totalTokens = 120,
+            sequence = 10,
+            sessionSequence = 5,
+        )
+        val jsonStr = ProtocolSerializer.encodeServerMessage(msg)
+        assert(jsonStr.contains("\"type\":\"router.narration\"")) { "expected type=router.narration" }
+        assert(jsonStr.contains("\"content\":\"moving on\"")) { "expected content" }
+        assert(jsonStr.contains("\"latencyMs\":2000")) { "expected latencyMs=2000" }
+        assert(jsonStr.contains("\"totalTokens\":120")) { "expected totalTokens=120" }
+    }
+
     @Test
     fun `SessionAnnounced round-trips through JSON`() {
         val original = ServerMessage.SessionAnnounced(