Update prompt-tutor integration example: no Review scroll keys

[shayan-ys]

📝 Summary

prompt-tutor no longer scrolls its own Review (shayan-ys/prompt-tutor feat/drop-review-scroll): --once is as tall as its content and the scroll-up/scroll-down actions are gone. This updates the prompt-tutor integration example to match; devdash's own scrolling (#19) now handles a long Review.

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🛠️ Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• ⚡ Performance / Refactor (code optimization without behavior changes)
• 📚 Documentation update

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🔍 Changes Made

• README prompt-tutor section: --once sized by COLUMNS only; example drops LINES, raises max_rows to 100, removes J/K keys, and points long Reviews to the dashboard's scroll keys.

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✅ Review and verification

• Review path: low-risk self-review (README only); no optional reviews.
• Verification: CI green; devdash --once renders the prompt-tutor section with the updated config.