🎨 Palette: Add help tooltips to complex input parameters

[aarjava]

Added help tooltips with concrete examples to vol_q_high and bt_cost inputs in src/dashboard.py to improve UI accessibility and intuitiveness for financial terminology.

Also added a critical UX learning to the Palette journal regarding explaining statistical parameters.

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PR created automatically by Jules for task 8700014032721004188 started by @aarjava

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