fix embedded images on deviantart

backend/src/main/java/com/storycove/service/HtmlSanitizationService.java

@@ -137,12 +137,63 @@ public class HtmlSanitizationService {
         return config;
     }
     
+    /**
+     * Preprocess HTML to extract images from figure tags before sanitization
+     */
+    private String preprocessFigureTags(String html) {
+        if (html == null || html.trim().isEmpty()) {
+            return html;
+        }
+
+        try {
+            org.jsoup.nodes.Document doc = Jsoup.parse(html);
+            org.jsoup.select.Elements figures = doc.select("figure");
+
+            for (org.jsoup.nodes.Element figure : figures) {
+                // Find img tags within the figure
+                org.jsoup.select.Elements images = figure.select("img");
+
+                if (!images.isEmpty()) {
+                    // Extract the first image and replace the figure with it
+                    org.jsoup.nodes.Element img = images.first();
+
+                    // Check if there's a figcaption to preserve as alt text
+                    org.jsoup.select.Elements figcaptions = figure.select("figcaption");
+                    if (!figcaptions.isEmpty() && !img.hasAttr("alt")) {
+                        String captionText = figcaptions.first().text();
+                        if (captionText != null && !captionText.trim().isEmpty()) {
+                            img.attr("alt", captionText);
+                        }
+                    }
+
+                    // Replace the figure element with just the img
+                    figure.replaceWith(img.clone());
+                    logger.debug("Extracted image from figure tag: {}", img.attr("src"));
+                } else {
+                    // No images in figure, remove it entirely
+                    figure.remove();
+                    logger.debug("Removed figure tag without images");
+                }
+            }
+
+            return doc.body().html();
+        } catch (Exception e) {
+            logger.warn("Failed to preprocess figure tags, returning original HTML: {}", e.getMessage());
+            return html;
+        }
+    }
+
     public String sanitize(String html) {
         if (html == null || html.trim().isEmpty()) {
             return "";
         }
+
         logger.info("Content before sanitization: "+html);
-        String saniztedHtml = Jsoup.clean(html, allowlist.preserveRelativeLinks(true));
+
+        // Preprocess to extract images from figure tags
+        String preprocessed = preprocessFigureTags(html);
+
+        String saniztedHtml = Jsoup.clean(preprocessed, allowlist.preserveRelativeLinks(true));
         logger.info("Content after sanitization: "+saniztedHtml);
         return saniztedHtml;
     }