fix: 趋势页恢复体重 + 图标换Material Icons + VLM禁用思考模式

- 健康概览页恢复体重指标的标签/单位/加载/筛选/录入
- 历史记录图标从emoji改为Material Icons
- VLM请求显式设置enable_thinking=false，禁用混合思考加速识图

health_app/lib/pages/chart/trend_page.dart

@@ -27,6 +27,7 @@ class _TrendPageState extends ConsumerState<TrendPage> {
     {'key': 'heart_rate', 'label': '心率', 'color': Color(0xFFF59E0B)},
     {'key': 'glucose', 'label': '血糖', 'color': Color(0xFF4F6EF7)},
     {'key': 'spo2', 'label': '血氧', 'color': Color(0xFF20C997)},
+    {'key': 'weight', 'label': '体重', 'color': Color(0xFF845EF7)},
   ];
 
   static const _units = {
@@ -34,6 +35,7 @@ class _TrendPageState extends ConsumerState<TrendPage> {
     'heart_rate': 'bpm',
     'glucose': 'mmol/L',
     'spo2': '%',
+    'weight': 'kg',
   };
 
   static const _names = {
@@ -41,6 +43,7 @@ class _TrendPageState extends ConsumerState<TrendPage> {
     'heart_rate': '心率',
     'glucose': '血糖',
     'spo2': '血氧',
+    'weight': '体重',
   };
 
   String get _unit => _units[_selected] ?? '';
@@ -60,7 +63,7 @@ class _TrendPageState extends ConsumerState<TrendPage> {
     setState(() => _loading = true);
     try {
       final api = ref.read(apiClientProvider);
-      final types = ['BloodPressure', 'HeartRate', 'Glucose', 'SpO2'];
+      final types = ['BloodPressure', 'HeartRate', 'Glucose', 'SpO2', 'Weight'];
       final all = <Map<String, dynamic>>[];
       for (final t in types) {
         try {
@@ -110,7 +113,9 @@ class _TrendPageState extends ConsumerState<TrendPage> {
         ? 'HeartRate'
         : _selected == 'glucose'
         ? 'Glucose'
-        : 'SpO2';
+        : _selected == 'spo2'
+        ? 'SpO2'
+        : 'Weight';
     setState(() {
       _filtered = _allRecords.where((r) => r['type'] == typeName).toList();
       _filtered.sort(
@@ -200,7 +205,9 @@ class _TrendPageState extends ConsumerState<TrendPage> {
                           ? 'HeartRate'
                           : _selected == 'glucose'
                           ? 'Glucose'
-                          : 'SpO2',
+                          : _selected == 'spo2'
+                          ? 'SpO2'
+                          : 'Weight',
                       'source': 'Manual',
                       'recordedAt': DateTime.now().toUtc().toIso8601String(),
                       'unit': _unit,
@@ -607,9 +614,10 @@ class _TrendPageState extends ConsumerState<TrendPage> {
                       borderRadius: BorderRadius.circular(10),
                     ),
                     child: Center(
-                      child: Text(
+                      child: Icon(
                         _getMetricIcon(_selected),
-                        style: const TextStyle(fontSize: 21),
+                        size: 21,
+                        color: _color,
                       ),
                     ),
                   ),
@@ -667,18 +675,20 @@ class _TrendPageState extends ConsumerState<TrendPage> {
     );
   }
 
-  String _getMetricIcon(String key) {
+  IconData _getMetricIcon(String key) {
     switch (key) {
       case 'blood_pressure':
-        return '🫀';
+        return Icons.monitor_heart_outlined;
       case 'heart_rate':
-        return '💓';
+        return Icons.favorite_border;
       case 'glucose':
-        return '🩸';
+        return Icons.water_drop_outlined;
       case 'spo2':
-        return '🫁';
+        return Icons.air_outlined;
+      case 'weight':
+        return Icons.monitor_weight_outlined;
       default:
-        return '📊';
+        return Icons.show_chart;
     }
   }
 }