Add actual chart/graph visualization for leaderboard data

[Muskankr]

The nav icon suggests a bar-chart visualization is intended, but the page currently only has a text-based error state with no visible chart structure. Once data loads, render it as an actual bar chart (most matched/missing skills), not just a list.

Acceptance criteria:
Skills rendered as a bar chart (e.g. via recharts) with clear labels
Readable in both light and dark mode
Responsive down to mobile width

[SohammPawarr]

Hi @Muskankr, I would love to tackle this data visualization issue—could you please assign it to me?
I'll integrate a library like recharts to render a displaying the matched and missing skills data.
To ensure mobile responsiveness, I will wrap the visualization in a ResponsiveContainer set to 100% width.
I will style the chart's axes, tooltips, and bar fills using the app's CSS variables so it adapts seamlessly to both light and dark modes.
Finally, I'll connect the loaded data state to conditionally render this chart instead of the text list.