Replace public distribution with winner claim lifecycle

[Birdmannn]

Pull Request Template

Description

this PR closes #405

test(giveaway): add two edge-case tests for claim lifecycle

What changed

test.rs

Added two tests to cover gaps in the existing claim lifecycle suite:

test_pick_winner_emits_winner_selected_event
Verifies that pick_winner emits a GiveawayWinnerSelected event with the correct topics (giveaway, winner, winner address) and that the prize_amount in the data vec equals the full gross share before any fee deduction.

test_partial_claim_creator_receives_exact_unclaimed_gross_shares
3-winner giveaway where only winner-0 claims before the deadline. After the window expires, asserts the creator recovers exactly the two unclaimed gross shares with no fee deduction on recovery, and the contract retains only the fee from the single successful claim.

Test results

• 143 → 145 passing, 0 failing

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Checklist

• I have tested my changes locally
• I have updated documentation as needed
• I have run npx prisma generate after schema changes
• I have run npx prisma migrate dev or npx prisma migrate deploy as appropriate

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Post-Merge Steps for Maintainers

If this PR includes changes to the Prisma schema:

1. Run the following command to apply the migration to your database:

   npx prisma migrate deploy

   or, for local development:

   npx prisma migrate dev

2. Ensure your CI pipeline runs the migration before tests (add this step if missing):

   - name: Run Prisma Migrate
     run: npx prisma migrate deploy

3. Make sure the database user in CI has permission to run migrations.

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If you have any questions, please comment on this PR.