This PR restricts usage of the LLM service to accounts older than 30
days.
We now store the GitHub user's `created_at` timestamp to check the
GitHub account age. If this is not set—which it won't be for existing
users—then we use the `created_at` timestamp in the Zed database.
Release Notes:
- N/A
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Co-authored-by: Max <max@zed.dev>
Don't allow granting guests write access in a call where the channel
or one of its ancestors requires the zed CLA, until that guest has
signed the Zed CLA.
Co-authored-by: Marshall <marshall@zed.dev>
