SCRUM-19-FE: Dashboard page

[anelka777]

The Dashboard Page is implemented according to the UX/UI design, with mock data and partial logic prepared for future backend integration.

[nataliasirt]

It’s well organized, feels like it will be nice to use, and the data handling is clean and ready to hook up later.
One thing to note: several new dashboard components use non‑Tailwind classes (w-104.75, h-33, w-169, h-88.75, w-30.5, max-w-200, h-9.75) and an invalid color class (text-(--color-surface)). Without a custom Tailwind config, these won’t apply and the layout will break. Affected: StatCard.tsx (line 34), StatCard.tsx (line 46), SetGoalModal.tsx (line 33), SetGoalModal.tsx (line 75), StudyHighlights.tsx (line 66), StudyHistory.tsx (line 145). Thank you - good job!