fix: bound Gateway transaction polling

[Mabolla]

Summary

• Bound Circle transaction confirmation polling to 90 attempts (~3 minutes).
• Centralized Gateway attestation polling with a 60-attempt limit.
• Added handling for non-successful Gateway API responses.
• Reused the same bounded polling behavior across EOA and custodial transfer paths.

Why

The custodial transfer and transaction-confirmation paths used unbounded polling loops. If Circle or Gateway never returned a terminal state, a server request could remain pending indefinitely.

The EOA path already used a bounded polling loop. This change removes the duplicated logic and makes both transfer paths consistent.

Validation

• npm run build ✅
• git diff --check ✅

Existing upstream issues

npm ci currently fails on master because package.json and package-lock.json contain mismatched dependency versions, including @circle-fin/developer-controlled-wallets.

npm run lint also reaches an existing ESLint circular-configuration error. This PR does not modify dependency or lint configuration files.