fix: update S3 cache rule for index.html

[rmnbrd]

Summary

Issue: Slack thread

"Importing a module script failed" errors

We're having a lot of "Importing a module script failed" errors. The bug seems to happen a lot on Safari, which applies heuristic caching when Cache-Control is absent, but uses a different algorithm compared to Chrome-based browsers.

When neither Cache-Control nor Expires is present, an HTTP cache may assign a heuristic freshness lifetime. This is standardized in RFC 9111 §4.2.2:

Since origin servers do not always provide explicit expiration times, a cache MAY assign a heuristic expiration time when an explicit time is not specified, employing algorithms that use other field values (such as the Last-Modified time) to estimate a plausible expiration time. This specification does not provide specific algorithms, but it does impose worst-case constraints on their results.

The fix is for index.html to not be cached, by adding a Cache-Control: 'no-cache' header.

Sources

Why you should use Cache-Control: no-store on index.html
HTTP Heuristic Caching

Screenshots / Recordings

Testing

• Changes tested locally in the relevant Console's pages and Storybooks
• yarn test or yarn test -u (if you need to regenerate snapshots)
• yarn format
• yarn lint

PR Checklist

• I followed naming, styling, and TypeScript rules (see .cursor/rules)
• I performed a self-review (diff inspected, dead code removed)
• I titled the PR using Conventional Commits with a scope when possible (e.g. feat(service): add new Terraform service) - required for semantic-release
• I only kept necessary comments, written in English (watch for useless AI comments)
• I involved a designer to validate UI changes if I am not a designer
• I covered new business logic with tests (unit)
• I confirmed CI is green (Codecov red can be accepted)
• I reviewed and executed locally any AI-assisted code

[Copilot]

Pull request overview

Updates the GitHub Actions deploy workflow to set explicit Cache-Control headers when uploading the built Console to S3, aiming to prevent stale index.html from being cached (notably in Safari) while allowing long-term caching for static assets.

Changes:

• Upload non-index.html artifacts with long-lived cache headers.
• Upload index.html last with Cache-Control: no-store to avoid stale SPA entrypoints.

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