docs: optimize PR review workflow for efficiency

Improve the PR review command workflow to reduce API calls and clarify
the review process:

- Fetch PR details in single call (combine list + view data)
- Add quick rejection checks before API calls (conflicts, duplicates)
- Simplify terminology (APPROVE/REJECT -> PASS/REJECT)
- Streamline section headers for clarity
- Remove gh pr view from allowed tools (redundant with list)

This reduces unnecessary GitHub API calls and makes the review process
more efficient.

Co-Authored-By: Claude <[email protected]>