Enhance AutoComplete keyboard interaction for Space key

- Add dedicated handler for Space key press in AutoComplete
- Trigger selection on Space key when a focused option exists
- Maintain existing Enter key behavior for option selection

packages/primevue/src/autocomplete/AutoComplete.vue

@@ -387,10 +387,13 @@ export default {
 
                 case 'Enter':
                 case 'NumpadEnter':
-                case 'Space':
                     this.onEnterKey(event);
                     break;
 
+                case 'Space':
+                    this.onSpaceKey(event);
+                    break;
+
                 case 'Escape':
                     this.onEscapeKey(event);
                     break;
@@ -705,6 +708,11 @@ export default {
 
             event.preventDefault();
         },
+        onSpaceKey(event) {
+            if (this.focusedOptionIndex !== -1) {
+                this.onEnterKey(event);
+            }
+        },
         onEscapeKey(event) {
             this.overlayVisible && this.hide(true);
             event.preventDefault();