[Brief to Build Spec] - Turns messy client notes into a build specification without hiding unknowns

Turn scattered client notes, emails, tickets, transcripts, and existing-product evidence into a build-ready specification. This skill separates confirmed requirements from proposals and unknowns, maps workflows and failure states, exposes hidden data/integration/security work, drafts testable acceptance criteria, ranks owner decisions, and returns READY, PATCH, or BLOCKED. It never invents frameworks, deadlines, budgets, or approvals. Built for freelancers, agencies, and product teams.