Ultra code review can now post its findings as a GitHub PR comment

What

• /code-review ultra gained new --post/--no-post flags that drive an end-to-end flow for posting an ultra code review's findings to a GitHub.com pull request as a single comment, via a new server route. A large set of specific, user-facing refusal or error messages cover cases like being rate-limited, not logged in, GitHub not connected, permission denied, or findings still pending.
• When a cloud code review is configured to post its findings to the pull request from the user's own GitHub account, the initial "Cloud review completed" notification now notes that the posting is happening asynchronously and that a follow-up notification will report the outcome, and advises against applying the findings locally unless that was also requested.

Why

This lets a review's findings be shared directly on the pull request for others to see, without the user manually copying them over, while keeping the user informed about what's still in progress and what not to do while it finishes.