Before: Claude Code hits "node not found", installs node, hits "go not found", installs go, hits "docker not found"... still misses things.

After: runs `openboot init --check --json` first, sees node/go/docker all missing at once, installs everything in one shot.

openboot reads package.json, go.mod, Cargo.toml, 15+ file types. `openboot setup-agent` writes the rule automatically. Works with Codex too.