chore(clean up): remove unused imports, unnecessary object impls, concurrency/coroutine issues, trailing commas, etc.

infrastructure/persistence/src/main/kotlin/com/correx/infrastructure/persistence/artifact/LiveArtifactRepository.kt

@@ -25,7 +25,7 @@ import java.util.concurrent.*
 
 class LiveArtifactRepository(
     private val eventStore: EventStore,
-    private val reducer: ArtifactReducer,
+    reducer: ArtifactReducer,
     private val scope: CoroutineScope = CoroutineScope(Dispatchers.IO + SupervisorJob()),
 ) : ArtifactRepository {
 
@@ -41,8 +41,8 @@ class LiveArtifactRepository(
 
     override fun getByStage(sessionId: SessionId, stageId: StageId): Map<ArtifactId, ArtifactState> {
         ensureSubscribed(sessionId)
-        val cache = artifactCache[sessionId] ?: emptyMap<ArtifactId, ArtifactState>()
-        val index = stageIndex[sessionId] ?: emptyMap<ArtifactId, StageId>()
+        val cache = artifactCache[sessionId] ?: emptyMap()
+        val index = stageIndex[sessionId] ?: emptyMap()
         return cache.filter { (artifactId, _) -> index[artifactId] == stageId }
     }