fix: VLM识别修复 + 饮食CRUD + 侧边栏美化 + UI优化

- VLM: ChatMessage.Content string→object, 修复视觉content双重序列化
- 饮食: diet/medication端点 record→手动JSON解析, 修复循环引用
- 饮食记录: 左滑删除 + 去评分 + AI饮食评语(DeepSeek)
- 侧边栏: 功能区统一Row+Expanded, 服务包compact模式
- 历史对话: 点击加载历史消息
- 登录页: 居中布局, 去底部空白
- UI: 主色加深#6C5CE7, maxWidth:1024防图片超大

health_app/lib/pages/diet/diet_capture_page.dart

@@ -6,6 +6,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:image_picker/image_picker.dart';
 import '../../core/navigation_provider.dart';
 import '../../providers/auth_provider.dart';
+import '../../utils/sse_handler.dart';
 
 final dietProvider = NotifierProvider<DietNotifier, DietState>(DietNotifier.new);
 
@@ -16,6 +17,7 @@ class DietState {
   final bool isAnalyzing;
   final int? healthScore;
   final String? errorMessage;
+  final String? commentary;
 
   DietState({
     this.imagePath,
@@ -24,6 +26,7 @@ class DietState {
     this.isAnalyzing = false,
     this.healthScore,
     this.errorMessage,
+    this.commentary,
   });
 
   DietState copyWith({
@@ -33,6 +36,7 @@ class DietState {
     bool? isAnalyzing,
     int? healthScore,
     String? errorMessage,
+    String? commentary,
   }) {
     return DietState(
       imagePath: imagePath ?? this.imagePath,
@@ -41,6 +45,7 @@ class DietState {
       isAnalyzing: isAnalyzing ?? this.isAnalyzing,
       healthScore: healthScore ?? this.healthScore,
       errorMessage: errorMessage ?? this.errorMessage,
+      commentary: commentary ?? this.commentary,
     );
   }
 }
@@ -92,16 +97,34 @@ class DietNotifier extends Notifier<DietState> {
 
       final raw = data['data'] as String? ?? '[]';
       final foods = _parseFoodItems(raw);
-      state = state.copyWith(
-        foods: foods,
-        isAnalyzing: false,
-        healthScore: foods.isNotEmpty ? 3 : null,
-      );
+      state = state.copyWith(foods: foods, isAnalyzing: false, healthScore: foods.isNotEmpty ? 3 : null);
+      if (foods.isNotEmpty) _fetchCommentary(foods);
     } catch (e) {
       state = state.copyWith(isAnalyzing: false, errorMessage: '识别失败，请重试');
     }
   }
 
+  Future<void> _fetchCommentary(List<FoodItem> foods) async {
+    try {
+      final api = ref.read(apiClientProvider);
+      final token = await api.accessToken;
+      if (token == null) return;
+      final names = foods.map((f) => '${f.name}(${f.portion},${f.calories}kcal)').join('、');
+      final stream = SseHandler.connect(
+        agentType: 'default',
+        message: '我刚才吃了这些：$names。请结合我的健康档案，给我简短的饮食评价和建议（50字以内）。',
+        token: token,
+      );
+      String text = '';
+      await for (final event in stream) {
+        if (event['action'] == 'answer') text += (event['data'] as String?) ?? '';
+        if (event['action'] == 'status') {
+          if (text.isNotEmpty) state = state.copyWith(commentary: text.trim());
+        }
+      }
+    } catch (_) {}
+  }
+
   List<FoodItem> _parseFoodItems(String raw) {
     var json = raw.trim();
     if (json.startsWith('```')) {
@@ -274,7 +297,7 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
 
   Future<void> _pickImage(BuildContext context, WidgetRef ref, ImageSource source) async {
     final picker = ImagePicker();
-    final picked = await picker.pickImage(source: source, imageQuality: 85);
+    final picked = await picker.pickImage(source: source, imageQuality: 80, maxWidth: 1024, maxHeight: 1024);
     if (picked != null) {
       ref.read(dietProvider.notifier).setImage(picked.path);
       ref.read(dietProvider.notifier).analyzeImage();
@@ -289,17 +312,21 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
       padding: const EdgeInsets.all(16),
       child: Column(children: [
         _buildImagePreview(state.imagePath!),
-        const SizedBox(height: 20),
+        const SizedBox(height: 16),
         _buildMealSelector(context, ref),
-        const SizedBox(height: 20),
-        if (state.isAnalyzing) _buildAnalyzingIndicator(state) else _buildFoodList(context, ref),
-        if (!state.isAnalyzing && state.foods.isNotEmpty) ...[
-          const SizedBox(height: 20),
-          _buildNutritionSummary(totalCalories),
-          const SizedBox(height: 20),
-          _buildHealthScore(state.healthScore ?? 0),
-          const SizedBox(height: 30),
-          _buildSubmitButton(context, ref),
+        const SizedBox(height: 16),
+        if (state.isAnalyzing) _buildAnalyzingIndicator(state) else ...[
+          _buildFoodList(context, ref),
+          if (state.foods.isNotEmpty) ...[
+            const SizedBox(height: 16),
+            _buildNutritionSummary(totalCalories),
+            if (state.commentary != null && state.commentary!.isNotEmpty) ...[
+              const SizedBox(height: 16),
+              _buildAiCommentary(state.commentary!),
+            ],
+            const SizedBox(height: 24),
+            _buildSubmitButton(context, ref),
+          ],
         ],
       ]),
     );
@@ -502,6 +529,21 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
     );
   }
 
+  Widget _buildAiCommentary(String text) {
+    return Container(
+      padding: const EdgeInsets.all(14),
+      decoration: BoxDecoration(
+        gradient: const LinearGradient(colors: [Color(0xFFEDEAFF), Color(0xFFF5F3FF)], begin: Alignment.topLeft, end: Alignment.bottomRight),
+        borderRadius: BorderRadius.circular(16),
+      ),
+      child: Row(crossAxisAlignment: CrossAxisAlignment.start, children: [
+        Container(width: 32, height: 32, decoration: BoxDecoration(color: const Color(0xFF6C5CE7).withAlpha(20), borderRadius: BorderRadius.circular(10)), child: const Icon(Icons.auto_awesome, size: 16, color: Color(0xFF6C5CE7))),
+        const SizedBox(width: 10),
+        Expanded(child: Text(text, style: const TextStyle(fontSize: 14, color: Color(0xFF444444), height: 1.5))),
+      ]),
+    );
+  }
+
   String _getScoreComment(int score) {
     switch (score) {
       case 1: return '饮食不太健康，建议多吃蔬菜';