fix: missing To field when only other fields are filled

lib/features/composer/presentation/widgets/recipient_composer_widget.dart

@@ -325,8 +325,7 @@ class _RecipientComposerWidgetState extends State<RecipientComposerWidget> {
           ),
           if (widget.prefix == widget.prefixRootState && _isWeb && !isMobileResponsive)
             ..._buildListPrefixWidgets(),
-          if (widget.prefix == widget.prefixRootState && (isMobileResponsive || widget.isTestingForWeb))
-            _buildExpandButton(),
+          if (_isShowExpandButton(isMobileResponsive)) _buildExpandButton(),
           if (widget.prefix != widget.prefixRootState && _isWeb && !isMobileResponsive)
             TMailButtonWidget.fromIcon(
               icon: widget.imagePaths.icClose,
@@ -400,6 +399,24 @@ class _RecipientComposerWidgetState extends State<RecipientComposerWidget> {
     ];
   }
 
+  bool _isShowExpandButton(bool isMobileResponsive) {
+    final onlyCcEnabled = widget.toState == PrefixRecipientState.disabled &&
+        widget.ccState == PrefixRecipientState.enabled;
+
+    final onlyBccEnabled = widget.toState == PrefixRecipientState.disabled &&
+        widget.ccState == PrefixRecipientState.disabled &&
+        widget.bccState == PrefixRecipientState.enabled;
+
+    final shouldCheckPrefix = switch (widget.prefix) {
+      PrefixEmailAddress.to => widget.toState == PrefixRecipientState.enabled,
+      PrefixEmailAddress.cc => onlyCcEnabled,
+      PrefixEmailAddress.bcc => onlyBccEnabled,
+      _ => false,
+    };
+
+    return shouldCheckPrefix && (isMobileResponsive || widget.isTestingForWeb);
+  }
+
   Widget _buildExpandButton() {
     return TMailButtonWidget.fromIcon(
       key: Key('prefix_${widget.prefix.name}_recipient_expand_button'),