fix: RecentActivity uses the wrong icons for each metric

[Mkalbani]

File: src/components/RecentActivity.tsx

Problem
The activity card renders:

• call.svg next to groupSize ("Call a friend" icon for group size?)
• audience.svg next to participants
• 50-50.svg next to earnings

None of those icons match their label semantically.

Expected

• Map icons to the data they represent:
  • groupSize → users.svg (or similar people icon)
  • participants → same / variant
  • earnings → coins.svg
  • Also use activity.coins.gold / activity.coins.red instead of a hardcoded 🏆.
• Add proper alt text per icon (alt="" for purely decorative icons is fine once the mapping is correct).

Acceptance

• Visual review confirms each icon matches its metric.
• Any unused assets (call.svg, 50-50.svg here) are removed from this component.

[webdevayo]

Hello Maintainer, would like to work on this project. Please assign to me ...

[jesutobaadedejidev]

I want to work on this issue. Do assign it to me.

[gloskull]

Can i work on this?

[gloskull]

Can i work on this?

[Kenisank]

Hi maintainer, I would like to solve this issue