feat(leaderboard): add hotness-weighted ranking for hall of fame

[KurosawaGeeker]

Background

The current hall of fame / leaderboard appears to rank users mostly by the generated score. As a result, once very famous or legacy GitHub users are checked, they can immediately jump to the top and stay there for a long time.

Problem

This makes the leaderboard easy to dominate by a few historically high-score accounts:

• Community-active users and ordinary users become hard to discover.
• The top of the leaderboard becomes relatively static after well-known users are added.
• The ranking does not reflect current community activity or recent interest.

Proposal

Add a composite ranking model that combines hotness + score instead of relying only on the roast score / total score.

Possible signals:

• Roast score or GitHub profile score, normalized.
• Recent query/check count.
• Recent unique visitors or unique users who checked the profile.
• Time decay, so old entries gradually lose ranking weight unless they continue to receive attention.
• Optional separate tabs such as Trending and All-time if preserving the existing all-time ranking is still useful.

The exact formula can be adjusted, but the key point is that old high-score accounts should not permanently occupy the top of the default leaderboard.

Expected outcome

• The default leaderboard surfaces users with both strong scores and recent activity.
• Famous legacy accounts can still rank highly when they are currently popular, but they should not permanently dominate only because they were checked once.
• Community-active users and normal users have a realistic chance to appear near the top.

[QGrain]

@KurosawaGeeker This issue has been addressed by pr #25 and can be closed.