Summary

Safari doesn't respect cache: 'no-cache' the same way Chrome and Firefox do. When fetching /index.html with no-cache, Safari would still serve the response from its HTTP cache. This caused problems after new Playground deployments—the stale cached index.html contained references to assets that no longer existed on the server, breaking the site.

This PR switches to cache: 'no-store' in all fetch operations, which makes Safari behave consistently with other browsers by always going to the network without checking the HTTP cache first.

Changes

• Replace cache: 'no-cache' with cache: 'no-store' in networkFirstFetch()
• Apply the same fix to cacheOfflineModeAssetsForCurrentRelease() and fetchFresh()
• Add detailed comment explaining the Safari-specific behavior and why no-store is required

Test plan

• Deploy to staging and verify Safari loads the latest version after deployment
• Test that offline mode still works correctly in Safari
• Verify behavior is unchanged in Chrome and Firefox