Agent Skills: stop

Anti-premature-coding protocol. MANDATORY pre-coding checkpoint: execute BEFORE writing ANY code (new features, bug fixes, refactoring, optimization, tests). Use when user requests: "implement/add/fix/refactor/optimize/create feature". Prevents "coding without reading" blindspot that causes most bugs, duplicated work, and broken architectures. Forces systematic investigation via Stop→Trace→Orient→Plan before touching keyboard.