fix: correct drag and drop target detection for result association columns

- Fix getDropTarget function to properly detect drops on column bodies
- Allow dropping on any element within the column body area
- Ensure drag and drop associations work correctly

mbetterclient/web_dashboard/templates/dashboard/extraction.html

@@ -900,9 +900,10 @@ document.addEventListener('DOMContentLoaded', function() {
     }
 
     function getDropTarget(element) {
-        // Check for outcome column body
-        if (element.hasAttribute('data-drop-target')) {
-            return element.closest('.outcome-column');
+        // Check for outcome column body (or any element inside it)
+        const columnBody = element.closest('[data-drop-target]');
+        if (columnBody) {
+            return columnBody.closest('.outcome-column');
         }
 
         // Check for UNDER/OVER zones