Remove unnecessary FG warning from EHLD validator

FG is optional and the warning was noise in validation output.

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

Author: adamjohnwright

src/main/java/org/reactome/server/tools/EhldValidator.java

@@ -23,7 +23,6 @@
  *   4. LOGO exists somewhere inside BG
  *   5. At least one REGION-R-HSA-[numbers] group exists
  *   6. Each REGION has a matching OVERLAY inside it
- *   7. FG is optional (warning if missing)
  */
 public class EhldValidator implements Checker {
 
@@ -136,12 +135,6 @@ private void validateSvg(File svgFile) {
             }
         }
 
-        // Check FG (optional, just warn)
-        Element fgElement = findElementById(topGroup, "FG");
-        if (fgElement == null) {
-            logger.warn("EHLD '{}': no 'FG' group found (optional)", filename);
-        }
-
         // Check REGION-R-HSA-[numbers] groups
         List<Element> regions = findElementsMatchingId(topGroup, REGION_PATTERN);
         if (regions.isEmpty()) {