feat(errors): add centralized exception handling

src/stores/chat/chat-send-flow.ts

@@ -1,5 +1,6 @@
 import { fromCallback, fromPromise } from "xstate";
 
+import { ExceptionHandler } from "@/core/errors";
 import { MessageQueue } from "@/core/net/message-queue";
 import type { ChatSendResponse } from "@/data/dto/chat";
 import { getChatRepository } from "@/data/repositories/chat_repository";
@@ -131,8 +132,7 @@ function createMessageQueueActor(
       const output = await sendMessageViaHttp(content);
       sendBack({ type: "ChatQueuedHttpDone", output });
     } catch (error) {
-      const errorMessage =
-        error instanceof Error ? error.message : "Message send failed";
+      const errorMessage = ExceptionHandler.message(error);
       log.error("[chat-machine] message queue send failed", {
         error,
       });