Physical SIM activation was failing with error 210 "アカウント不在エラー" (Account not found) because PA02-01 requires the SIM to be pre-registered in Freebit's system. This adds PA05-18 (Semi-Black Account Registration) as the first step before PA02-01. New flow: PA05-18 → PA02-01 → PA05-05 Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>