feat: move checkout to dedicated page and add member check logic

feat: include branch name in point history reason

feat: add created_by_name for manual cashier input

feat: track member creation details and point history log

fix: rename MemberID to MemberCode in struct to prevent GORM type mismatch panic

fix: members API 401 unauthorized by extracting companyID from user context

feat: add Member service, points, and Kasir Name tracking