feat: show GitHub contribution graph in the card background

[bae080311]

What's the idea

Show the user’s GitHub contribution graph on the profile page that opens when clicking the GitFut card.
The contribution graph would not be displayed directly on the card itself.

Problem it solves

The profile page currently has limited information about the user’s actual GitHub activity.
Adding the contribution graph would make the page more informative and better connected to the user’s GitHub profile.

How it might work

When a user clicks a GitFut card and opens the detailed profile page, the page could fetch and display their GitHub contribution graph.
It could appear below the card or in a separate activity section.
I’d be happy to work on this and open a PR if the idea is accepted.

Alternatives

Instead of the full contribution graph, the page could show a simplified heatmap or recent contribution activity.

[Younesfdj]

Hey @bae080311

I'd genuinely like to see how this looks before committing. so consider the idea accepted for a PR, with merge depending on the visual result. A few things that will make it land smoothly:

1. There's already contribution-grid DNA on that page. the faint grid motif along the bottom of the backdrop (components/Background.tsx, fake data, pure decoration). A real per-user graph should either replace that strip with real data or reuse its exact cell style (.gf-grid-cell, same cell size/rounding/green) so the page doesn't end up with two different-looking contribution grids.

2. No new API calls needed. the scout already fetches the full contributionCalendar (per-day counts) in the profile query; we just reduce it to a number today. Wire the data through from there rather than adding a fetch (if it's not really needed).

3. Please include screenshots at mobile/tablet/desktop and a couple of card tiers in the PR. that's what the merge decision will mostly be based on, and vitest coverage for whatever pure transform you add (calendar → panel data).

Looking forward to seeing it 👍