fix: deadline-asc sort no longer ranks expired bounties as soonest

[smartcalsystems-sketch]

Problem

deadline-asc sorted by raw timestamp, so an already-expired deadline (the smallest timestamp) ranked first. A contributor choosing "Deadline: soonest" would see bounties they can no longer complete ahead of urgent-but-still-open ones.

Fix

Captures now once per sort call, classifies each deadline as expired or not, and ranks every non-expired deadline before every expired one. Within each group, ordering is still ascending by timestamp (soonest-upcoming first among open bounties; longest-expired first among expired ones). Bounties with no deadline are unaffected and still sort last, as before.

Testing

• Added a test with a mix of near/far-future, recently/long-expired, and no-deadline bounties, asserting open ones rank before expired ones regardless of raw timestamp magnitude.
• Full bounty-query.test.ts suite: 23/23 passing (22 pre-existing + 1 new), zero regressions.
• tsc --noEmit and eslint clean on both changed files.

Closes #703

[vercel]

@smartcalsystems-sketch is attempting to deploy a commit to the chonilius' projects Team on Vercel.

A member of the Team first needs to authorize it.