docs: Star History README chart times out after 10 seconds #202

Summary

The GitHub stargazer access restriction required Raven to move from the legacy anonymous Star History SVG to the official token-based embed flow.

The token setup is complete and the interactive chart works on star-history.com. However, the README embed is still blank because the Star History image service times out while fetching Raven's star history.

Current state

• A fine-grained token is scoped to EverMind-AI/Raven with Metadata read-only access.
• The interactive chart renders successfully when the token is stored in the browser.
• Star History generated the official sealed-token README embed.
• The embed is implemented in docs: add authenticated star history chart #200.
• Direct requests to the Star History /chart, /image, and /svg endpoints consistently return HTTP 500 after about 10.9 seconds.
• The response body reports: Repo evermind-ai/raven: timeout of 10000ms exceeded.

This indicates that the repository access problem has been resolved by the token, but the end-to-end README rendering problem has not been fully resolved.

Investigation

We need to determine what the observed 10-second limit represents:

• Is 10,000 ms an overall Star History server request timeout or an upstream GitHub request timeout?
• Is there any time-window, cooldown, cache-warmup, or rate-limit behavior that can make a later request succeed?
• Does fetching and paginating Raven's roughly 2.5K stargazers exceed a fixed request budget?
• Can Star History cache, paginate, or resume the fetch so the README image endpoint returns reliably?
• Can a failed response remain cached by GitHub's image proxy after the upstream service recovers?

The current evidence shows a request timeout. It does not yet establish that GitHub's API rate limit is the cause.

Expected behavior

The sealed-token endpoint should return a valid chart image reliably so GitHub can render the real-time Star History curve in the README.

References

• Related pull request: docs: add authenticated star history chart #200
• Star History access restriction notice: https://www.star-history.com/blog/github-stargazer-api-restriction/
• Star History token and README embed flow: https://www.star-history.com/blog/how-to-use-github-star-history/
• GitHub access restriction announcement: https://github.blog/changelog/2026-06-30-upcoming-access-restrictions-to-public-api-endpoints-and-ui-views/