🎨 Palette: Add contextual help tooltips to financial inputs

[aarjava]

💡 What: Added help tooltips to the "High Volatility Quantile" and "Transaction Cost (bps)" inputs in the sidebar. The tooltips contain concrete examples (e.g. 10 bps = 0.10%). Also added a journal entry to .Jules/palette.md to record the UX learning regarding concrete financial thresholds.

🎯 Why: Complex financial or statistical inputs can be ambiguous to users or screen readers. Adding concrete, numerical examples reduces cognitive load, grounds the input, and makes the dashboard more accessible to users with varied levels of financial expertise.

📸 Before/After:
Before: The sliders/inputs simply said "High Volatility Quantile" or "Transaction Cost (bps)" with no further context on hover.
After: The inputs now have hoverable "?" tooltips providing an exact example (e.g. 0.80 = top 20% most volatile days).

♿ Accessibility: Improves clarity for cognitive accessibility by grounding ambiguous parameters with literal examples. Tooltips are native Streamlit components and therefore natively accessible to screen readers.

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PR created automatically by Jules for task 7521839264289823694 started by @aarjava

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