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/pages/diet/diet_capture_page.dart

@@ -132,11 +132,11 @@ class DietCapturePage extends ConsumerWidget {
             width: 180,
             height: 180,
             decoration: BoxDecoration(
-              color: const Color(0xFFF2FAF9),
+              color: const Color(0xFFF0F2FF),
               borderRadius: BorderRadius.circular(90),
-              border: Border.all(color: const Color(0xFF14B8A6), width: 2),
+              border: Border.all(color: const Color(0xFF8B9CF7), width: 2),
             ),
-            child: const Icon(Icons.camera_alt, size: 48, color: Color(0xFF14B8A6)),
+            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)),
@@ -165,10 +165,10 @@ class DietCapturePage extends ConsumerWidget {
           decoration: BoxDecoration(
             color: const Color(0xFFFEFEFF),
             borderRadius: BorderRadius.circular(20),
-            boxShadow: [BoxShadow(color: const Color(0xFF14B8A6).withAlpha(20), blurRadius: 8, offset: const Offset(0, 2))],
+            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(0xFF14B8A6)),
+            icon: Icon(icon, size: 32, color: const Color(0xFF8B9CF7)),
             onPressed: () => _pickImage(context, ref, source),
           ),
         ),
@@ -244,11 +244,11 @@ class DietCapturePage extends ConsumerWidget {
               child: Column(children: [
                 Text(meal['icon']!, style: const TextStyle(fontSize: 20)),
                 const SizedBox(height: 4),
-                Text(meal['label']!, style: TextStyle(fontSize: 12, color: isSelected ? Colors.white : const Color(0xFF14B8A6))),
+                Text(meal['label']!, style: TextStyle(fontSize: 12, color: isSelected ? Colors.white : const Color(0xFF8B9CF7))),
               ]),
               style: ElevatedButton.styleFrom(
-                backgroundColor: isSelected ? const Color(0xFF14B8A6) : const Color(0xFFF2FAF9),
-                foregroundColor: isSelected ? Colors.white : const Color(0xFF14B8A6),
+                backgroundColor: isSelected ? const Color(0xFF8B9CF7) : const Color(0xFFF0F2FF),
+                foregroundColor: isSelected ? Colors.white : const Color(0xFF8B9CF7),
                 elevation: 0,
                 shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(16)),
                 padding: const EdgeInsets.symmetric(vertical: 12),
@@ -268,10 +268,10 @@ class DietCapturePage extends ConsumerWidget {
           height: 60,
           padding: const EdgeInsets.all(12),
           decoration: BoxDecoration(
-            color: const Color(0xFFE6FAF6),
+            color: const Color(0xFFF0F2FF),
             borderRadius: BorderRadius.circular(30),
           ),
-          child: const CircularProgressIndicator(strokeWidth: 3, color: Color(0xFF14B8A6)),
+          child: const CircularProgressIndicator(strokeWidth: 3, color: Color(0xFF8B9CF7)),
         ),
         const SizedBox(height: 16),
         const Text('AI 正在识别食物...', style: TextStyle(fontSize: 16, color: Color(0xFF666666))),
@@ -286,7 +286,7 @@ class DietCapturePage extends ConsumerWidget {
       decoration: BoxDecoration(
         color: const Color(0xFFFEFEFF),
         borderRadius: BorderRadius.circular(20),
-        border: Border.all(color: const Color(0xFFD4EDE8), width: 1.5),
+        border: Border.all(color: const Color(0xFFD8DCFD), width: 1.5),
       ),
       child: Column(children: [
         Padding(
@@ -297,7 +297,7 @@ class DietCapturePage extends ConsumerWidget {
             const Text('识别结果', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600)),
             const Spacer(),
             IconButton(
-              icon: const Icon(Icons.add, size: 20, color: Color(0xFF14B8A6)),
+              icon: const Icon(Icons.add, size: 20, color: Color(0xFF8B9CF7)),
               onPressed: () => ref.read(dietProvider.notifier).addFood(),
             ),
           ]),
@@ -312,14 +312,14 @@ class DietCapturePage extends ConsumerWidget {
       margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
       padding: const EdgeInsets.all(12),
       decoration: BoxDecoration(
-        color: food.selected ? const Color(0xFFF2FAF9) : const Color(0xFFF5F5F5),
+        color: food.selected ? const Color(0xFFF0F2FF) : const Color(0xFFF5F5F5),
         borderRadius: BorderRadius.circular(16),
       ),
       child: Row(children: [
         Checkbox(
           value: food.selected,
           onChanged: (v) => ref.read(dietProvider.notifier).toggleFood(food.id),
-          activeColor: const Color(0xFF14B8A6),
+          activeColor: const Color(0xFF8B9CF7),
         ),
         const SizedBox(width: 8),
         Expanded(
@@ -339,7 +339,7 @@ class DietCapturePage extends ConsumerWidget {
                   controller: TextEditingController(text: food.calories.toString()),
                   keyboardType: TextInputType.number,
                   onChanged: (v) => ref.read(dietProvider.notifier).updateFoodCalories(food.id, int.tryParse(v) ?? 0),
-                  style: TextStyle(fontSize: 12, color: const Color(0xFF14B8A6)),
+                  style: TextStyle(fontSize: 12, color: const Color(0xFF8B9CF7)),
                 ),
               ),
               const Text('kcal', style: TextStyle(fontSize: 12, color: Color(0xFF999999))),
@@ -358,7 +358,7 @@ class DietCapturePage extends ConsumerWidget {
     return Container(
       padding: const EdgeInsets.all(16),
       decoration: BoxDecoration(
-        color: const Color(0xFFF2FAF9),
+        color: const Color(0xFFF0F2FF),
         borderRadius: BorderRadius.circular(16),
       ),
       child: Row(children: [
@@ -383,7 +383,7 @@ class DietCapturePage extends ConsumerWidget {
       decoration: BoxDecoration(
         color: const Color(0xFFFEFEFF),
         borderRadius: BorderRadius.circular(20),
-        border: Border.all(color: const Color(0xFFD4EDE8), width: 1.5),
+        border: Border.all(color: const Color(0xFFD8DCFD), width: 1.5),
       ),
       child: Column(children: [
         const Text('🥗 健康评分', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600)),
@@ -417,7 +417,7 @@ class DietCapturePage extends ConsumerWidget {
     switch (score) {
       case 1: return const Color(0xFFE53935);
       case 2: return const Color(0xFFF9A825);
-      case 3: return const Color(0xFF14B8A6);
+      case 3: return const Color(0xFF8B9CF7);
       case 4: return const Color(0xFF43A047);
       case 5: return const Color(0xFF00C853);
       default: return Colors.grey[400]!;
@@ -431,13 +431,13 @@ class DietCapturePage extends ConsumerWidget {
         onPressed: () {
           ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
             content: Text('饮食记录已保存 ✅'),
-            backgroundColor: Color(0xFF14B8A6),
+            backgroundColor: Color(0xFF8B9CF7),
           ));
           popRoute(ref);
         },
         child: const Text('保存记录'),
         style: ElevatedButton.styleFrom(
-          backgroundColor: const Color(0xFF14B8A6),
+          backgroundColor: const Color(0xFF8B9CF7),
           foregroundColor: Colors.white,
           shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(24)),
           padding: const EdgeInsets.symmetric(vertical: 16),