fix: stabilize tied creator sorting and share seed helper

[charlesedeh021-cell]

Closes #596

Changes

• Adds shared creator market seed helpers for integration coverage.
• Stabilizes creator list sorting with an id tie-breaker for deterministic pagination.
• Adds live integration coverage for tied creator price sorting across pages.
• Refactors the wallet holdings snapshot test to reuse the shared seed helpers.

Testing

• git diff --check
• pnpm build attempted, but the local pnpm/node_modules environment timed out/failed before a clean project build could complete.
• pnpm exec tsc --noEmit attempted with the same local environment limitation.