Function aggregate

pkg/hooks/executor.go:427–567

aggregate combines per-hook results into a single [Result].

(results []hookResult, event EventType)

// aggregate combines per-hook results into a single [Result].
func aggregate(results []hookResult, event EventType) *Result {
	final := &Result{Allowed: true}
	var messages, contexts, sysMsgs []string

	for _, r := range results {
		switch {
		case r.err != nil:
			policy := ErrorPolicy(r.hook.OnError)
			if policy == "" {
				policy = ErrorPolicyWarn
			}
			if failClosed(event) || policy == ErrorPolicyBlock {
				slog.Warn("Hook failed; blocking event", "hook", r.hook.DisplayName(), "error", r.err)
				final.Allowed = false
				final.ExitCode = -1
				final.Stderr = r.Stderr
				messages = append(messages, fmt.Sprintf("PreToolUse hook failed to execute: %v", r.err))
			} else if policy != ErrorPolicyIgnore {
				slog.Warn("Hook execution error", "hook", r.hook.DisplayName(), "error", r.err)
			}
			continue

		case r.ExitCode == 2:
			final.Allowed = false
			final.ExitCode = 2
			if r.Stderr != "" {
				final.Stderr = r.Stderr
				messages = append(messages, strings.TrimSpace(r.Stderr))
			}
			continue

		case r.ExitCode != 0:
			slog.Debug("Hook returned non-zero exit code", "exit_code", r.ExitCode, "stderr", r.Stderr)
			continue

		case r.Output == nil:
			// Plain stdout becomes AdditionalContext only for events
			// whose runtime consumes it.
			if r.Stdout != "" && stdoutAsContext(event) {
				contexts = append(contexts, strings.TrimSpace(r.Stdout))
			}
			continue
		}

		out := r.Output
		if !out.ShouldContinue() {
			final.Allowed = false
			if out.StopReason != "" {
				messages = append(messages, out.StopReason)
			}
		}
		if out.IsBlocked() {
			final.Allowed = false
			if out.Reason != "" {
				messages = append(messages, out.Reason)
			}
		}
		if out.SystemMessage != "" {