Feat: automatically collapse search bar when focus is lost

frontend/lib/ui/shared/inputs/app_search_bar.dart

@@ -64,7 +64,13 @@ class _AppSearchBarState extends ConsumerState<AppSearchBar> {
   }
 
   void _onFocusChanged() {
-    if (mounted) setState(() {});
+    if (mounted) {
+      setState(() {
+        if (!_focusNode.hasFocus && widget.collapsible) {
+          _isExpanded = false;
+        }
+      });
+    }
     
     if (_focusNode.hasFocus && widget.enableHistory) {
       _showOverlay();
@@ -199,6 +205,17 @@ class _AppSearchBarState extends ConsumerState<AppSearchBar> {
   @override
   Widget build(BuildContext context) {
     if (!_isExpanded && widget.collapsible) {
+      if (_hasText) {
+        return IconButton(
+          onPressed: () {
+            _controller.clear();
+            widget.onChanged?.call('');
+            if (widget.onSubmitted != null) widget.onSubmitted!('');
+          },
+          icon: const Icon(Icons.close, size: 28, color: Colors.redAccent),
+          tooltip: 'Clear search',
+        );
+      }
       return IconButton(
         onPressed: () {
           setState(() => _isExpanded = true);