build-brieflisted

# Step 4: Build (บรีฟให้ชัด ไม่ใช่แค่สั่ง) **Habit**: H5 — Seek First to Understand | **Anti-pattern**: Prompting "build X" without reading existing code ## Process 0. **Problem statement gate** (REQUIRED before anything else): > "What specific problem does this implementation solve?" Must cite one of: requirement (issue #), bug report, or design decision (ADR). If you cannot answer this question, go back to `/requirements` first. Research basis: Amazon Working Backwards, Basecamp Shape Up, and Google Design Docs all physically separate "what & why" from "how". Teams that skip this waste 30-40% of implementation time on rework. 1. **Read existing code and context first**: Before writing anything new, read the files in the affected area. Also read repo context files when present: `DOMAIN.md`, `SPEC.md`, `CONTEXT.md`, `CONTEXT-MAP.md`, `docs/agents/domain.md`, and relevant ADRs. Understand current patterns, naming conventions, glossary terms, and architecture. 1b. **Check past lessons** (if `~/.claude/lessons/` exists): - Grep `~/.claude/lessons/` for tags or keywords matching the task name, affected file paths, or domain - Search by tags first: `Grep pattern="tags:.*<keyword>" path="~/.claude/lessons/"` - Fall back to keyword search: `Grep pattern="<keyword>" path="~/.claude/lessons/"` - If relevant lessons found, include them in the context brief under "Lessons from past work" - If no lessons directory or no matches, skip silently 2. **Buil