chore(ci): switch Claude Code review model from sonnet to opus

Use claude-opus-4 for higher-quality PR reviews via the /review skill.

Author: fyzanshaik-atlan

.github/workflows/claude.yml

@@ -48,6 +48,6 @@ jobs:
         with:
           anthropic_api_key: ${{ secrets.LITELLM_API_KEY }}
           claude_args: |
-            --model claude-sonnet-4
+            --model claude-opus-4
             --allowedTools "mcp__github_inline_comment__create_inline_comment"
             --append-system-prompt "CRITICAL INSTRUCTION: When a user asks you to review a pull request (e.g. @claude review, @claude review this PR, @claude please review), you MUST execute the /review slash command. Do NOT attempt a freeform review. Always use the /review skill — no exceptions."