Claude auto reviewer: set model and sticky comment

[mattezra]

No description provided.

[github-actions]

Code Review

Overview: This PR makes three improvements to the Claude auto-reviewer GitHub Actions workflow:

1. Adds use_sticky_comment: true so the reviewer updates a single comment per PR rather than posting a new one on each synchronize event — cleaner UX and avoids comment spam.
2. Pins the model to claude-sonnet-4-6 for consistency and reproducibility.
3. Raises --max-turns to 25 to allow the reviewer to handle larger/more complex PRs.

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Looks good overall. A few notes:

• Empty PR body — the description is blank. Even a one-liner explaining why these values were chosen (e.g. the default turn limit was too low for multi-file PRs) would help future maintainers.

• Model pinning — claude-sonnet-4-6 is the right ID format. Keep in mind this will need a manual update when you want to move to a newer model; it won't auto-upgrade. That's usually the desired behaviour for CI workflows, so this is fine.

• --max-turns 25 — see inline comment. This is functionally fine but worth a note for cost awareness.

• use_sticky_comment + cancel-in-progress: true — these two settings pair well together: rapid-fire pushes cancel the in-flight review and the sticky comment gets a single final update rather than a pile of partial comments.

No blocking issues. Changes are low-risk configuration adjustments.