Add generate_image tool and show Codex images inline

internal/agents/codex.go

@@ -3,6 +3,7 @@ package agents
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"log/slog"
 	"os"
 	"strings"
@@ -143,6 +144,16 @@ func (m *Manager) codexItemCompleted(ctx context.Context, l *live, s *codex.Sess
 			return nil
 		}
 		return m.emit(ctx, l, agentActor, "agent.thinking", map[string]any{"text": text})
+
+	case codex.ThreadItemTypeImageGeneration:
+		if item.SavedPath == "" || l.reviewID != "" || l.owner != "" {
+			return nil
+		}
+		path, err := copyToMedia(MediaDir(l.dir), string(item.SavedPath))
+		if err != nil {
+			return err
+		}
+		return m.emit(ctx, l, agentActor, "agent.message", map[string]any{"text": fmt.Sprintf("![%s](<%s>)", imageAlt(item.RevisedPrompt), path)})
 	}
 
 	if !codexToolItems[item.Type] {
@@ -188,6 +199,17 @@ func (m *Manager) codexItemCompleted(ctx context.Context, l *live, s *codex.Sess
 	return nil
 }
 
+func imageAlt(prompt string) string {
+	alt := strings.NewReplacer("[", "", "]", "", "\n", " ").Replace(strings.TrimSpace(prompt))
+	if r := []rune(alt); len(r) > 120 {
+		alt = string(r[:120]) + "…"
+	}
+	if alt == "" {
+		return "generated image"
+	}
+	return alt
+}
+
 func codexToolResult(item codex.ThreadItem) (string, bool) {
 	status := codexStatus(item)
 	switch item.Type {