ci: run the PR reviewer agent on opus at high effort

[thomaspinder]

Summary

The pr-reviewer agent now sets its own model, effort and blocked tools.

 ---
 name: pr-reviewer
 description: ...
+model: opus
+effort: high
+disallowedTools: Edit, Write, NotebookEdit
 ---

• model: opus: with no model set, the first review (GPJax#808) ran on Sonnet 5.5.
• effort: high: Opus 5.5 defaults to medium.
• disallowedTools: the prompt already says "You do not edit files". This line enforces it. It is disallowedTools, not a tools: allowlist, so the action's comment tools stay available.

The workflow passes no --model, so the frontmatter decides. claude --agent pr-reviewer uses the same settings locally.

Evidence

• Before: the GPJax#808 run log shows "model": "claude-sonnet-5-5".
  After: the session init event from claude -p --agent pr-reviewer --output-format stream-json --verbose:

  model = claude-opus-5-5
  Edit, Write, NotebookEdit -> absent
  Read                      -> present
  

• The init event does not report effort. effort in frontmatter applies when the agent runs as the main session, per the Claude Code subagent docs.

Merge Danger

Door: two-way

Remove the three lines to revert.

Blast Radius: isolated

Only @claude-pr-review runs change. Each review uses more Claude subscription quota than on Sonnet.

🤖 Generated with Claude Code

[github-actions]

📖 Docs preview: https://pr-814--endearing-crepe-c2d5fe.netlify.app

Smoke render — the expensive notebooks run with reduced budgets, so
figures are not publication fidelity. /render-mode.txt says smoke.