Added Production-Like Testing for Custom Themes

Local testing only goes so far. The custom-theme runtime can now be deployed for production-style testing. Account-level setup work, media upload fixes, CDN routing, and serverless rendering support make this a significant step toward launching custom themes in production.

Closing the local-to-production gap

Basker can now test a real custom theme against site data outside a local development environment. This closes the gap that often causes surprises after launch: a theme that works locally but behaves differently under CDN routing, serverless rendering, or production media paths can now be validated before it matters.

Confidence before go-live

For teams approaching their first launch, the ability to verify theme behaviour in a production-like environment changes the risk profile of a handover. Problems that would previously surface on launch day can now be caught and resolved during the review period.