fix: diet capture flow - 去掉多余页面，点击直接拍照

- 点击"拍照识别/上传照片"直接打开相机/相册，不再跳转多余选择页
- DietCapturePage 去掉重复的拍照按钮，只保留分析结果展示
- 新增 dietActionProvider 处理拍饮食触发
- 修复 initState reset 导致结果页被清空的 bug
- 修复 IP 地址恢复问题

health_app/lib/pages/diet/diet_capture_page.dart

@@ -230,7 +230,7 @@ class DietCapturePage extends ConsumerStatefulWidget {
 class _DietCapturePageState extends ConsumerState<DietCapturePage> {
   @override void initState() {
     super.initState();
-    Future.microtask(() => ref.read(dietProvider.notifier).reset());
+    // 不 reset — 图片由 home_page 传入，这里只做展示
   }
 
   @override
@@ -242,74 +242,12 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
         title: const Text('拍饮食'),
         centerTitle: true,
       ),
-      body: state.imagePath == null ? _buildCaptureView(context, ref) : _buildResultView(context, ref),
+      body: state.imagePath == null
+          ? const Center(child: Text('请从首页拍摄或选择食物照片', style: TextStyle(color: Color(0xFF999999))))
+          : _buildResultView(context, ref),
     );
   }
 
-  Widget _buildCaptureView(BuildContext context, WidgetRef ref) {
-    return Center(
-      child: Column(
-        mainAxisSize: MainAxisSize.min,
-        children: [
-          Container(
-            width: 180,
-            height: 180,
-            decoration: BoxDecoration(
-              color: const Color(0xFFF0F2FF),
-              borderRadius: BorderRadius.circular(90),
-              border: Border.all(color: const Color(0xFF8B9CF7), width: 2),
-            ),
-            child: const Icon(Icons.camera_alt, size: 48, color: Color(0xFF8B9CF7)),
-          ),
-          const SizedBox(height: 24),
-          const Text('拍摄或上传您的餐食照片', style: TextStyle(fontSize: 18, fontWeight: FontWeight.w500)),
-          const SizedBox(height: 8),
-          const Text('AI将识别食物并分析营养成分', style: TextStyle(fontSize: 14, color: Color(0xFF999999))),
-          const SizedBox(height: 40),
-          Row(
-            mainAxisAlignment: MainAxisAlignment.center,
-            children: [
-              _captureBtn(context, ref, Icons.camera_alt, '拍照', ImageSource.camera),
-              const SizedBox(width: 24),
-              _captureBtn(context, ref, Icons.photo_library, '相册', ImageSource.gallery),
-            ],
-          ),
-        ],
-      ),
-    );
-  }
-
-  Widget _captureBtn(BuildContext context, WidgetRef ref, IconData icon, String label, ImageSource source) {
-    return Column(
-      children: [
-        Container(
-          width: 80,
-          height: 80,
-          decoration: BoxDecoration(
-            color: const Color(0xFFFEFEFF),
-            borderRadius: BorderRadius.circular(20),
-            boxShadow: [BoxShadow(color: const Color(0xFF8B9CF7).withAlpha(20), blurRadius: 8, offset: const Offset(0, 2))],
-          ),
-          child: IconButton(
-            icon: Icon(icon, size: 32, color: const Color(0xFF8B9CF7)),
-            onPressed: () => _pickImage(context, ref, source),
-          ),
-        ),
-        const SizedBox(height: 8),
-        Text(label, style: const TextStyle(fontSize: 14, color: Color(0xFF666666))),
-      ],
-    );
-  }
-
-  Future<void> _pickImage(BuildContext context, WidgetRef ref, ImageSource source) async {
-    final picker = ImagePicker();
-    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();
-    }
-  }
-
   // ─────────── 设计常量（与项目整体色调一致）───────────
   static const _kPrimary = AppTheme.primary;      // #6C5CE7
   static const _kPrimaryLight = AppTheme.primaryLight; // #EDEAFF