🎨 Palette: Add concrete examples to statistical tooltips

[aarjava]

As the UX-focused agent 'Palette', I identified an opportunity to improve the usability of the configuration sidebar. Many of the inputs (like 'Quantiles', 'ADV', and 'bps') use dense financial or statistical terminology.

This PR adds native Streamlit help tooltips to these inputs, providing simple, concrete real-world examples (e.g., mapping 10 bps to 0.10%). This micro-interaction makes the interface significantly more intuitive without adding visual clutter or new dependencies.

Changes:

• Added help text with concrete examples to factor_window, vol_window, adv_pct, vol_q_high, and bt_cost in src/dashboard.py.
• Formatted modified lines cleanly using Black.
• Recorded the UX insight in the .Jules/palette.md journal.

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PR created automatically by Jules for task 10006661756295590944 started by @aarjava

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