feat: add mlack.uk custom domain route to production

[mahata]

Summary

• Adds a custom domain route (mlack.uk) to the production environment in wrangler.toml
• Cloudflare Workers will serve the app at https://mlack.uk instead of only the *.workers.dev subdomain

[Copilot]

Pull request overview

This PR updates the Cloudflare Wrangler production configuration to serve the Worker on the custom domain mlack.uk, aligning production access with the desired public hostname rather than relying solely on the *.workers.dev subdomain.

Changes:

• Add a production routes entry for mlack.uk with custom_domain = true in wrangler.toml.

Show a summary per file

File	Description
wrangler.toml	Adds a production custom domain route (mlack.uk) via Wrangler routes configuration.

Copilot's findings

• Files reviewed: 1/1 changed files
• Comments generated: 0