Function warn

test/e2e-agentic.mjs:28–28

const ok    = s => `${C.green}✅ ${s}${C.reset}`;
const fail  = s => `${C.red}❌ ${s}${C.reset}`;
const warn  = s => `${C.yellow}⚠  ${s}${C.reset}`;
const hdr   = s => `\n${C.bold}${C.cyan}━━━ ${s} ━━━${C.reset}`;
const tool  = s => `  ${C.magenta}🔧 ${s}${C.reset}`;
const info  = s => `  ${C.gray}${s}${C.reset}`;