fix(docs): harden i18n prompt failures

scripts/docs-i18n/translator.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"strings"
@@ -14,6 +13,7 @@ import (
 const (
 	translateMaxAttempts = 3
 	translateBaseDelay   = 15 * time.Second
+	translatePromptTimeout = 2 * time.Minute
 )
 
 var errEmptyTranslation = errors.New("empty translation")
@@ -145,96 +145,31 @@ func (t *PiTranslator) Close() {
 	}
 }
 
-type agentEndPayload struct {
-	Messages []agentMessage `json:"messages"`
+type promptRunner interface {
+	Run(context.Context, string) (pi.RunResult, error)
+	Stderr() string
 }
 
-type agentMessage struct {
-	Role         string          `json:"role"`
-	Content      json.RawMessage `json:"content"`
-	StopReason   string          `json:"stopReason,omitempty"`
-	ErrorMessage string          `json:"errorMessage,omitempty"`
-}
-
-type contentBlock struct {
-	Type string `json:"type"`
-	Text string `json:"text,omitempty"`
-}
-
-func runPrompt(ctx context.Context, client *pi.OneShotClient, message string) (string, error) {
-	events, cancel := client.Subscribe(256)
+func runPrompt(ctx context.Context, client promptRunner, message string) (string, error) {
+	promptCtx, cancel := context.WithTimeout(ctx, translatePromptTimeout)
 	defer cancel()
 
-	if err := client.Prompt(ctx, message); err != nil {
-		return "", err
-	}
-
-	for {
-		select {
-		case <-ctx.Done():
-			return "", ctx.Err()
-		case event, ok := <-events:
-			if !ok {
-				return "", errors.New("event stream closed")
-			}
-			if event.Type == "agent_end" {
-				return extractTranslationResult(event.Raw)
-			}
-		}
+	result, err := client.Run(promptCtx, message)
+	if err != nil {
+		return "", decoratePromptError(err, client.Stderr())
 	}
+	return result.Text, nil
 }
 
-func extractTranslationResult(raw json.RawMessage) (string, error) {
-	var payload agentEndPayload
-	if err := json.Unmarshal(raw, &payload); err != nil {
-		return "", err
+func decoratePromptError(err error, stderr string) error {
+	if err == nil {
+		return nil
 	}
-	for index := len(payload.Messages) - 1; index >= 0; index-- {
-		message := payload.Messages[index]
-		if message.Role != "assistant" {
-			continue
-		}
-		if message.ErrorMessage != "" || strings.EqualFold(message.StopReason, "error") {
-			msg := strings.TrimSpace(message.ErrorMessage)
-			if msg == "" {
-				msg = "unknown error"
-			}
-			return "", fmt.Errorf("pi error: %s", msg)
-		}
-		text, err := extractContentText(message.Content)
-		if err != nil {
-			return "", err
-		}
-		return text, nil
-	}
-	return "", errors.New("assistant message not found")
-}
-
-func extractContentText(content json.RawMessage) (string, error) {
-	trimmed := strings.TrimSpace(string(content))
+	trimmed := strings.TrimSpace(stderr)
 	if trimmed == "" {
-		return "", nil
+		return err
 	}
-	if strings.HasPrefix(trimmed, "\"") {
-		var text string
-		if err := json.Unmarshal(content, &text); err != nil {
-			return "", err
-		}
-		return text, nil
-	}
-
-	var blocks []contentBlock
-	if err := json.Unmarshal(content, &blocks); err != nil {
-		return "", err
-	}
-
-	var parts []string
-	for _, block := range blocks {
-		if block.Type == "text" && block.Text != "" {
-			parts = append(parts, block.Text)
-		}
-	}
-	return strings.Join(parts, ""), nil
+	return fmt.Errorf("%w (pi stderr: %s)", err, trimmed)
 }
 
 func normalizeThinking(value string) string {