Replace Yoroi account lookup with Blockfrost - #59

Bugbot Analysis Progress (1m 2s elapsed)

✅ Gathered PR context (4s)
✅ Completed bug detection (57s)
✅ Posted analysis results (1s)

Final Result: Bugbot completed review - no issues found! ✅

Request ID: serverGenReqId_772aebb7-8aa5-42ac-b6ce-37c1bdce91db