🎨 Palette: Improve dashboard table empty state

[myarichuk]

💡 What: Replaced the plain text empty state for characters/archives in the dashboard table with a rich layout containing an icon, title, and subtitle.
🎯 Why: To improve the onboarding and dashboard experience when a user hasn't created any characters yet, making the UI feel more polished and guiding them naturally.
📸 Before/After: Before, it was a single line of italic text (Your grimoire is empty. Begin an adventure to see history here.). After, it uses a larger icon (book-open) and clearer typography.
♿ Accessibility: Maintaining standard semantic HTML within the table.

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PR created automatically by Jules for task 11981767459565622470 started by @myarichuk

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