App crashes when sending messages with code blocks

[Tsukimarf]

Bug Report
Description
The application crashes when attempting to send a message containing code blocks.

Steps to Reproduce

Open the chat interface
Type a message that includes a code block (using ``` markdown syntax)
Send the message
Application crashes

Expected Behavior
The message with the code block should be sent successfully and rendered with syntax highlighting as shown in the features list.
Actual Behavior
The application crashes upon sending the message.
Environment

Node.js version: (e.g., v20.9.0)
Browser: (e.g., Chrome 120, Firefox 121, Safari 17)
Operating System: (e.g., macOS 14, Windows 11, Ubuntu 22.04)
Deployment: (local development / Netlify)