fix: prevent panic on short article content in archive cmd

Add length check before slicing article.Content[:32], matching the
safe truncation pattern already used in cmd/browser/main.go.

Closes #9

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sites/archive/cmd/archive/main.go

@@ -106,6 +106,15 @@ func main() {
 				return err
 			}
 
+			content := ""
+			if article.Content != "" {
+				if len(article.Content) > 32 {
+					content = article.Content[:32] + "..."
+				} else {
+					content = article.Content
+				}
+			}
+
 			fmt.Println("Title:", article.Title)
 			fmt.Println("Byline:", article.Byline)
 			fmt.Println("Site:", article.SiteName)
@@ -113,7 +122,7 @@ func main() {
 			fmt.Println("Excerpt:", article.Excerpt)
 			fmt.Println("Length:", article.Length)
 			fmt.Println("Lang:", article.Lang)
-			fmt.Println("Content:", article.Content[:32]+"...")
+			fmt.Println("Content:", content)
 			fmt.Println("TextContent:", article.TextContent)
 			return nil
 		},