feat: replace Code conversation archive with deletion

electron/api/coding-composition.ts

@@ -41,6 +41,7 @@ import { createDataServiceOperations } from '../services/data-service-client';
 import { createPreviewDataSessionManager, type PreviewDataSessionManager } from '../services/preview-data-session';
 import {
   archivePiConversationSession,
+  deletePiConversationSession,
   getPiManagedPaths,
 } from '../coding-runtime/pi/resource-loader';
 import { createProjectPluginService } from '../coding-plugins/project-service';
@@ -515,6 +516,9 @@ export function createCodingComposition(
   const conversations = new CodingConversationService(projects, runtime, {
     readHistory: (projectId, conversation) => readCodingConversationHistory(options.paths.userDataDir, projectId, conversation),
     onDelete: (projectId, conversationId) => teacher.removeSource(projectId, conversationId),
+    deleteSession: async ({ projectId, sessionKey }) => {
+      await deletePiConversationSession({ userDataDir: options.paths.userDataDir, projectId, sessionKey });
+    },
     archiveSession: async ({ projectId, sessionKey }) => {
       await archivePiConversationSession({
         userDataDir: options.paths.userDataDir,