Show contest prizes in discussion banners

[AgentGoose32]

Link to Issue

Closes: #8596

/claim #8596

Description of Changes

• Passes the existing contest balance from discussion-page active contests into ContestCard.
• This lets the discussion contest banner compute and display prize amounts immediately from the API payload instead of falling back to 0 while the on-chain balance query is unavailable/pending.
• Keeps the existing on-chain balance override in ContestCard when it is available.

Test Plan

• git diff --check
• Manual code inspection of discussion active contest rendering path.

Deployment Plan

• Normal frontend deploy.

Other Considerations

• Local dependency install was not present in this fresh checkout, so I kept validation to the changed TSX path and whitespace/diff checks.