fix: 胶囊高度42px + 功能卡片白底 + 面板绿粉渐变 + 间距调整

health_app/lib/pages/home/home_page.dart

@@ -186,7 +186,7 @@ class _HomePageState extends ConsumerState<HomePage> {
 
   Widget _buildAgentBar() {
     return SizedBox(
-      height: 46,
+      height: 42,
       child: ListView.separated(
         scrollDirection: Axis.horizontal,
         padding: const EdgeInsets.symmetric(horizontal: 14),
@@ -296,9 +296,9 @@ class _HomePageState extends ConsumerState<HomePage> {
       child: Column(
         mainAxisSize: MainAxisSize.min,
         children: [
-          const SizedBox(height: 10),
+          const SizedBox(height: 6),
           _buildAgentBar(),
-          const SizedBox(height: 8),
+          const SizedBox(height: 6),
           if (_pickedImagePath != null) _buildImagePreview(),
           _buildInputBar(),
         ],