docs(phase2.6): 사주 랜딩·입력 재스킨 구현 플랜 (3 Task) Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01AAtcmKKtqDUe4NyVgy1aLQ @