Struct headTailBuffer

internal/tools/bash.go:231–236

headTailBuffer is an io.Writer keeping the first bashOutputHead and the last bashOutputTail bytes written, discarding the middle. The tail is a fixed ring so a firehose costs a bounded copy, never an allocation per write.

		// an npm install) run twice: once to hit the deadline, once with a
		// bigger timeout. Clamp seconds BEFORE the Duration multiply: 1e18
		// would overflow int64 into a negative duration, and 0.5 would truncate
		// to 0 and cancel before the shell runs, so floor at 1.
		timeout := 10 * time.Minute
		if secs := intArg(call.Arguments, "timeout_seconds"); secs > 0 {
			timeout = time.Duration(min(max(secs, 1), maxBashTimeoutSeconds)) * time.Second
		}
		return Bash(parent, cmd, timeout)
	case WriteFileName:
		path, _ := call.Arguments["path"].(string)