Task 1: SyncHelpModal 신규 (4 anchor 섹션) Task 2: ConflictModal inline 설명 + onOpenHelp optional prop Task 3: SyncSection 도움말 버튼 + modal mount + ConflictModal wiring Task 4: README "원격 백업" → "동기화 (Git, Cut E)" 통째 재작성 각 task TDD (test → impl → typecheck → commit), 단위 +11. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>