feat: UI 清新风全面改造 — 朝露主题 + shadcn_ui + 全局字号放大

- 全新"朝露"主题：深青绿主色(#2D6A4F)，暖白底，完整设计Token
- 引入 shadcn_ui 组件库，MaterialApp 注入 ShadTheme
- 新增 4 个公共组件：AppCard、AppMenuItem、AppEmptyState、AppTabChip
- 全面消除硬编码颜色，统一使用 AppTheme Token
- 全局字号 +3~4pt，图标等比放大 +3px
- home/medication/profile/settings/login 等核心页面重写
- 路由和功能逻辑零改动

health_app/lib/pages/diet/diet_capture_page.dart

@@ -351,9 +351,9 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
                         : null,
                   ),
                   child: Column(mainAxisSize: MainAxisSize.min, children: [
-                    Icon(m.icon, size: 20, color: isSelected ? Colors.white : _kSubText),
+                    Icon(m.icon, size: 23, color: isSelected ? Colors.white : _kSubText),
                     const SizedBox(height: 4),
-                    Text(m.label, style: TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: isSelected ? Colors.white : _kSubText)),
+                    Text(m.label, style: TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: isSelected ? Colors.white : _kSubText)),
                   ]),
                 ),
               ),
@@ -376,15 +376,15 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
               alignment: Alignment.center,
               children: [
                 const CircularProgressIndicator(strokeWidth: 3, color: _kPrimary),
-                const Icon(Icons.restaurant, size: 22, color: _kPrimary),
+                const Icon(Icons.restaurant, size: 25, color: _kPrimary),
               ],
             ),
           ),
           const SizedBox(height: 20),
-          const Text('正在识别食物...', style: TextStyle(fontSize: 15, color: _kSubText)),
+          const Text('正在识别食物...', style: TextStyle(fontSize: 18, color: _kSubText)),
           if (state.errorMessage != null) ...[
             const SizedBox(height: 8),
-            Text(state.errorMessage!, style: const TextStyle(fontSize: 13, color: AppTheme.error), textAlign: TextAlign.center),
+            Text(state.errorMessage!, style: const TextStyle(fontSize: 16, color: AppTheme.error), textAlign: TextAlign.center),
           ],
         ]),
       ),
@@ -411,16 +411,16 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
               Container(
                 padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                 decoration: BoxDecoration(color: _kPrimaryLight, borderRadius: BorderRadius.circular(8)),
-                child: const Text('识别结果', style: TextStyle(fontSize: 13, fontWeight: FontWeight.w600, color: _kPrimary)),
+                child: const Text('识别结果', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: _kPrimary)),
               ),
               const Spacer(),
               Container(
                 padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 4),
                 decoration: BoxDecoration(color: const Color(0xFFFFF8EE), borderRadius: BorderRadius.circular(8)),
-                child: Text('共 $totalCal kcal', style: const TextStyle(fontSize: 13, fontWeight: FontWeight.w600, color: _kWarning)),
+                child: Text('共 $totalCal kcal', style: const TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: _kWarning)),
               ),
               IconButton(
-                icon: const Icon(Icons.add_circle_outline, size: 22, color: _kPrimary),
+                icon: const Icon(Icons.add_circle_outline, size: 25, color: _kPrimary),
                 padding: EdgeInsets.zero,
                 constraints: const BoxConstraints(),
                 onPressed: () => ref.read(dietProvider.notifier).addFood(),
@@ -457,7 +457,7 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
                   color: food.selected ? _kPrimary : Colors.white,
                   border: Border.all(color: food.selected ? _kPrimary : const Color(0xFFCCCCCC), width: 2),
                 ),
-                child: food.selected ? const Icon(Icons.check, size: 14, color: Colors.white) : null,
+                child: food.selected ? const Icon(Icons.check, size: 17, color: Colors.white) : null,
               ),
             ),
             const SizedBox(width: 12),
@@ -466,7 +466,7 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
                 TextField(
                   controller: TextEditingController(text: food.name),
                   onChanged: (v) => ref.read(dietProvider.notifier).updateFoodName(food.id, v),
-                  style: const TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: _kText),
+                  style: const TextStyle(fontSize: 18, fontWeight: FontWeight.w600, color: _kText),
                   decoration: const InputDecoration(
                     isDense: true,
                     contentPadding: EdgeInsets.zero,
@@ -480,13 +480,13 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
                     child: TextField(
                       controller: TextEditingController(text: food.portion),
                       onChanged: (v) => ref.read(dietProvider.notifier).updateFoodPortion(food.id, v),
-                      style: const TextStyle(fontSize: 12, color: _kSubText),
+                      style: const TextStyle(fontSize: 15, color: _kSubText),
                       decoration: const InputDecoration(
                         isDense: true,
                         contentPadding: EdgeInsets.zero,
                         border: InputBorder.none,
                         hintText: '份量',
-                        hintStyle: TextStyle(fontSize: 12, color: AppTheme.textHint),
+                        hintStyle: TextStyle(fontSize: 15, color: AppTheme.textHint),
                       ),
                     ),
                   ),
@@ -497,24 +497,24 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
                       controller: TextEditingController(text: food.calories.toString()),
                       onChanged: (v) => ref.read(dietProvider.notifier).updateFoodCalories(food.id, int.tryParse(v) ?? 0),
                       keyboardType: TextInputType.number,
-                      style: const TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: _kWarning),
+                      style: const TextStyle(fontSize: 15, fontWeight: FontWeight.w600, color: _kWarning),
                       textAlign: TextAlign.right,
                       decoration: const InputDecoration(
                         isDense: true,
                         contentPadding: EdgeInsets.zero,
                         border: InputBorder.none,
                         hintText: '0',
-                        hintStyle: TextStyle(fontSize: 12),
+                        hintStyle: TextStyle(fontSize: 15),
                       ),
                     ),
                   ),
                   const SizedBox(width: 2),
-                  const Text('kcal', style: TextStyle(fontSize: 11, color: _kSubText)),
+                  const Text('kcal', style: TextStyle(fontSize: 14, color: _kSubText)),
                 ]),
               ]),
             ),
             IconButton(
-              icon: const Icon(Icons.close, size: 16, color: Color(0xFFBBBBBB)),
+              icon: const Icon(Icons.close, size: 19, color: Color(0xFFBBBBBB)),
               padding: EdgeInsets.zero,
               constraints: const BoxConstraints(),
               onPressed: () => ref.read(dietProvider.notifier).removeFood(food.id),
@@ -552,8 +552,8 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
                   ),
                 ),
                 Column(mainAxisSize: MainAxisSize.min, children: [
-                  Text('$totalCalories', style: const TextStyle(fontSize: 14, fontWeight: FontWeight.w800, color: Colors.white)),
-                  Text('kcal', style: const TextStyle(fontSize: 10, color: Colors.white70)),
+                  Text('$totalCalories', style: const TextStyle(fontSize: 17, fontWeight: FontWeight.w800, color: Colors.white)),
+                  Text('kcal', style: const TextStyle(fontSize: 13, color: Colors.white70)),
                 ]),
               ],
             ),
@@ -561,7 +561,7 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
           const SizedBox(width: 16),
           Expanded(
             child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
-              const Text('本餐热量', style: TextStyle(fontSize: 14, color: Colors.white70)),
+              const Text('本餐热量', style: TextStyle(fontSize: 17, color: Colors.white70)),
               const SizedBox(height: 4),
               Row(children: [
                 Expanded(child: _macroBar('碳水', 0.55, const Color(0xFFFFF9C4))),
@@ -582,7 +582,7 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
       Row(children: [
         Container(width: 6, height: 6, decoration: BoxDecoration(color: color, shape: BoxShape.circle)),
         const SizedBox(width: 4),
-        Text(label, style: const TextStyle(fontSize: 10, color: Colors.white70)),
+        Text(label, style: const TextStyle(fontSize: 13, color: Colors.white70)),
       ]),
       const SizedBox(height: 3),
       ClipRRect(
@@ -607,10 +607,10 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
           Container(
             width: 32, height: 32,
             decoration: BoxDecoration(color: _kPrimaryLight, borderRadius: BorderRadius.circular(8)),
-            child: const Icon(Icons.auto_awesome, size: 16, color: _kPrimary),
+            child: const Icon(Icons.auto_awesome, size: 19, color: _kPrimary),
           ),
           const SizedBox(width: 10),
-          Expanded(child: Text(text, style: const TextStyle(fontSize: 13, color: _kText, height: 1.6))),
+          Expanded(child: Text(text, style: const TextStyle(fontSize: 16, color: _kText, height: 1.6))),
         ]),
       ),
     );
@@ -650,11 +650,11 @@ class _DietCapturePageState extends ConsumerState<DietCapturePage> {
             backgroundColor: _kPrimary,
             foregroundColor: Colors.white,
             elevation: 0,
-            shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(AppTheme.radiusMd)),
-            textStyle: const TextStyle(fontSize: 16, fontWeight: FontWeight.w600),
+            shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(AppTheme.rMd)),
+            textStyle: const TextStyle(fontSize: 19, fontWeight: FontWeight.w600),
           ),
           child: const Row(mainAxisAlignment: MainAxisAlignment.center, children: [
-            Icon(Icons.check_circle_outline, size: 20),
+            Icon(Icons.check_circle_outline, size: 23),
             SizedBox(width: 8),
             Text('保存记录'),
           ]),