fix(auth): 放大登录注册分段的可点击区域

lib/pages/auth/auth_form_widgets.dart

@@ -259,30 +259,34 @@ class _ModeTab extends StatelessWidget {
       key: segmentKey,
       behavior: HitTestBehavior.opaque,
       onTap: onTap,
-      child: Column(
+      // 文字 + 指示条只有约 32px 高，补上下各 6px 把可点区域撑到 44。
-        crossAxisAlignment: CrossAxisAlignment.start,
+      child: Padding(
-        mainAxisSize: MainAxisSize.min,
+        padding: const EdgeInsets.symmetric(vertical: 6),
-        children: [
+        child: Column(
-          Text(
+          crossAxisAlignment: CrossAxisAlignment.start,
-            label,
+          mainAxisSize: MainAxisSize.min,
-            style: TextStyle(
+          children: [
-              color: selected ? AppColors.textPrimary : AppColors.muted,
+            Text(
-              fontSize: AppDimens.followingSegmentFont,
+              label,
-              fontWeight: FontWeight.w400,
+              style: TextStyle(
-            ),
+                color: selected ? AppColors.textPrimary : AppColors.muted,
-          ),
+                fontSize: AppDimens.followingSegmentFont,
-          const SizedBox(height: AppDimens.followingSegmentIndicatorTopGap),
+                fontWeight: FontWeight.w400,
-          Container(
-            width: AppDimens.followingSegmentIndicatorWidth,
-            height: AppDimens.followingSegmentIndicatorHeight,
-            decoration: BoxDecoration(
-              color: selected ? AppColors.brandRed : AppColors.transparent,
-              borderRadius: BorderRadius.circular(
-                AppDimens.followingSegmentIndicatorRadius,
               ),
             ),
-          ),
+            const SizedBox(height: AppDimens.followingSegmentIndicatorTopGap),
-        ],
+            Container(
+              width: AppDimens.followingSegmentIndicatorWidth,
+              height: AppDimens.followingSegmentIndicatorHeight,
+              decoration: BoxDecoration(
+                color: selected ? AppColors.brandRed : AppColors.transparent,
+                borderRadius: BorderRadius.circular(
+                  AppDimens.followingSegmentIndicatorRadius,
+                ),
+              ),
+            ),
+          ],
+        ),
       ),
     );
   }