feat: implement PI core chat timeline

electron/api/route-handlers.ts

@@ -18,6 +18,7 @@ import { handleFileRoutes } from './routes/files';
 import { handleMeowaGameAssetsRoutes } from './routes/meowa-game-assets';
 import { handleAgentBrowserRoutes } from './routes/agent-browser';
 import { handleCodingFileRoutes } from './routes/coding-files';
+import { handleCodingAttachmentRoutes } from './routes/coding-attachments';
 import { handleCodingProjectRoutes } from './routes/coding-projects';
 import { handleCodingConversationRoutes } from './routes/coding-conversations';
 
@@ -45,6 +46,7 @@ export const hostApiRouteHandlers: readonly HostApiRouteHandler[] = [
   handleWorksRoutes,
   handleAgentBrowserRoutes,
   handleUserSyncRoutes,
+  handleCodingAttachmentRoutes,
   handleCodingProjectRoutes,
   handleCodingConversationRoutes,
   handleCodingFileRoutes,