Fix image links with optional titles

main.go

@@ -230,19 +230,20 @@ func isSnap() bool {
 
 // processMarkdownImages processes markdown source and converts relative image paths to data URIs
 func processMarkdownImages(markdown string, baseDir string) string {
-	// Process markdown image syntax: ![alt](path)
-	imgMarkdownRegex := regexp.MustCompile(`!\[([^\]]*)\]\(([^)]+)\)`)
+	// Process markdown image syntax: ![alt](path "optional title")
+	imgMarkdownRegex := regexp.MustCompile(`!\[([^\]]*)\]\(([^)\s]+)(\s+(?:"[^"]*"|'[^']*'|\([^)]*\)))?\)`)
 	markdown = imgMarkdownRegex.ReplaceAllStringFunc(markdown, func(match string) string {
 		parts := imgMarkdownRegex.FindStringSubmatch(match)
 		if len(parts) < 3 {
 			return match
 		}
 		alt := parts[1]
 		imgPath := parts[2]
+		title := parts[3]
 
 		if isRelativePath(imgPath) {
 			if dataURI := imageToDataURI(imgPath, baseDir); dataURI != "" {
-				return fmt.Sprintf("![%s](%s)", alt, dataURI)
+				return fmt.Sprintf("![%s](%s%s)", alt, dataURI, title)
 			}
 		}
 		return match

main_test.go

@@ -0,0 +1,65 @@
+package main
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/yuin/goldmark"
+)
+
+func TestProcessMarkdownImages(t *testing.T) {
+	baseDir := t.TempDir()
+	imagePath := filepath.Join(baseDir, "images", "diagram.png")
+	if err := os.MkdirAll(filepath.Dir(imagePath), 0755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(imagePath, []byte("image data"), 0644); err != nil {
+		t.Fatal(err)
+	}
+
+	tests := []struct {
+		name          string
+		markdown      string
+		wantTitleHTML string
+	}{
+		{
+			name:          "double-quoted title",
+			markdown:      `![Architecture diagram](images/diagram.png "Architecture diagram")`,
+			wantTitleHTML: `title="Architecture diagram"`,
+		},
+		{
+			name:          "single-quoted title",
+			markdown:      `![Architecture diagram](images/diagram.png 'Architecture diagram')`,
+			wantTitleHTML: `title="Architecture diagram"`,
+		},
+		{
+			name:          "parenthesized title",
+			markdown:      `![Architecture diagram](images/diagram.png (Architecture diagram))`,
+			wantTitleHTML: `title="Architecture diagram"`,
+		},
+		{
+			name:     "without title",
+			markdown: `![Architecture diagram](images/diagram.png)`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			processed := processMarkdownImages(tt.markdown, baseDir)
+			if !strings.Contains(processed, `data:image/png;base64,aW1hZ2UgZGF0YQ==`) {
+				t.Fatalf("image was not embedded: %s", processed)
+			}
+
+			var rendered bytes.Buffer
+			if err := goldmark.New().Convert([]byte(processed), &rendered); err != nil {
+				t.Fatal(err)
+			}
+			if tt.wantTitleHTML != "" && !strings.Contains(rendered.String(), tt.wantTitleHTML) {
+				t.Fatalf("rendered image lost its title attribute: %s", rendered.String())
+			}
+		})
+	}
+}