style: 淡薰紫 Lavender Breeze + UI修复

- 主色改淡薰紫 #8B9CF7 + 白底 清新风格
- 每个智能体卡不同淡色调
- 删除欢迎卡底部"或直接对我说"
- 运动创建/打卡接入 API
- 全项目薄荷绿→淡紫替换

health_app/lib/widgets/health_drawer.dart

@@ -32,7 +32,7 @@ class HealthDrawer extends ConsumerWidget {
                     onTap: () => pushRoute(ref, 'profile'),
                     child: CircleAvatar(
                       radius: 28,
-                      backgroundColor: const Color(0xFFE6FAF6),
+                      backgroundColor: const Color(0xFFF0F2FF),
                       child: Icon(Icons.person, size: 32, color: Theme.of(context).colorScheme.primary),
                     ),
                   ),
@@ -95,7 +95,7 @@ class HealthDrawer extends ConsumerWidget {
               child: Row(children: [
                 Text('历史对话', style: Theme.of(context).textTheme.labelMedium!.copyWith(fontWeight: FontWeight.w600)),
                 const Spacer(),
-                TextButton(onPressed: () => ref.invalidate(conversationListProvider), child: const Text('刷新', style: TextStyle(fontSize: 12, color: Color(0xFF14B8A6)))),
+                TextButton(onPressed: () => ref.invalidate(conversationListProvider), child: const Text('刷新', style: TextStyle(fontSize: 12, color: Color(0xFF8B9CF7)))),
               ]),
             ),
             conversations.when(
@@ -162,10 +162,10 @@ class _HealthMetricChip extends StatelessWidget {
       decoration: BoxDecoration(
         color: Colors.white,
         borderRadius: BorderRadius.circular(12),
-        border: Border.all(color: const Color(0xFFE6FAF6)),
+        border: Border.all(color: const Color(0xFFF0F2FF)),
       ),
       child: Row(mainAxisSize: MainAxisSize.min, children: [
-        Icon(icon, size: 14, color: const Color(0xFF14B8A6)),
+        Icon(icon, size: 14, color: const Color(0xFF8B9CF7)),
         const SizedBox(width: 4),
         Column(crossAxisAlignment: CrossAxisAlignment.start, mainAxisSize: MainAxisSize.min, children: [
           Text(label, style: TextStyle(fontSize: 10, color: Colors.grey[600])),
@@ -186,7 +186,7 @@ class _ConversationItem extends ConsumerWidget {
     return Container(
       margin: const EdgeInsets.symmetric(horizontal: 4, vertical: 2),
       decoration: BoxDecoration(
-        color: const Color(0xFFF6F9FB),
+        color: const Color(0xFFF8F9FC),
         borderRadius: BorderRadius.circular(10),
       ),
       child: ListTile(
@@ -194,10 +194,10 @@ class _ConversationItem extends ConsumerWidget {
           width: 28,
           height: 28,
           decoration: BoxDecoration(
-            color: const Color(0xFFE6FAF6),
+            color: const Color(0xFFF0F2FF),
             borderRadius: BorderRadius.circular(8),
           ),
-          child: Icon(_getAgentIcon(item.agent), size: 14, color: const Color(0xFF14B8A6)),
+          child: Icon(_getAgentIcon(item.agent), size: 14, color: const Color(0xFF8B9CF7)),
         ),
         title: Text(item.title, maxLines: 1, overflow: TextOverflow.ellipsis, style: const TextStyle(fontSize: 12, fontWeight: FontWeight.w500)),
         subtitle: Text(item.lastMessage, maxLines: 1, overflow: TextOverflow.ellipsis, style: TextStyle(fontSize: 10, color: Colors.grey[500])),