feat: enable custom domain route for preview proxy

- Enable workers_dev subdomain for fallback access
- Configure custom domain route for preview.trycheatcode.com
- DNS now managed by Cloudflare with free DDoS/WAF protection

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: iamjr15

preview-worker/wrangler.toml

@@ -2,10 +2,13 @@ name = "cheatcode-preview-proxy"
 main = "src/index.ts"
 compatibility_date = "2024-01-01"
 
-# Custom domain will be configured after deployment
-# routes = [
-#   { pattern = "preview.trycheatcode.com/*", zone_name = "trycheatcode.com" }
-# ]
+# Enable workers.dev subdomain
+workers_dev = true
+
+# Custom domain route
+routes = [
+  { pattern = "preview.trycheatcode.com/*", zone_name = "trycheatcode.com" }
+]
 
 [observability]
 enabled = true