feat: Cupertino滚轮选择器 + 品牌更名 + UI全面优化

- 日期/时间/次数选择器统一改为底部弹出Cupertino滚轮，无单位标签，双横线选区
- App更名为"小脉健康"，副标题"血管病患者的AI健康管理助手"
- 健康仪表盘及侧边栏移除体重指标，侧边栏背景改为蓝白渐变
- 健康档案按钮移入功能入口网格，与其他入口样式统一
- 记数据智能体配色改为绿色渐变(#A1FFCE→#69DB8F)
- 隐私协议/关于页从Text改为MarkdownBody正确渲染
- 运动计划/饮食记录卡片添加边框和阴影
- 服药次数从chip改为滚轮选择器
- 日期显示格式统一为空格分隔(1999 01 01)
- 健康档案页背景改为纯白

health_app/lib/core/app_theme.dart

@@ -1,7 +1,356 @@
+import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:shadcn_ui/shadcn_ui.dart';
 import 'app_colors.dart';
 
+const _pickerItemStyle = TextStyle(fontSize: 22, fontWeight: FontWeight.w500);
+const _lineColor = Color(0xFFCBD5E1);
+
+Widget _wrapPicker(Widget picker) {
+  return Stack(
+    children: [
+      picker,
+      Positioned(
+        top: 0,
+        bottom: 0,
+        left: 0,
+        right: 0,
+        child: IgnorePointer(
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              Container(height: 1, color: _lineColor),
+              const SizedBox(height: 38),
+              Container(height: 1, color: _lineColor),
+            ],
+          ),
+        ),
+      ),
+    ],
+  );
+}
+
+Future<DateTime?> showAppDatePicker(
+  BuildContext context, {
+  required DateTime initialDate,
+  DateTime? firstDate,
+  DateTime? lastDate,
+}) {
+  final minDate = firstDate ?? DateTime(1900);
+  final maxDate = lastDate ?? DateTime(2100);
+  var y = initialDate.year.clamp(minDate.year, maxDate.year);
+  var m = initialDate.month;
+  var d = initialDate.day;
+  final yearCtrl = FixedExtentScrollController(initialItem: y - minDate.year);
+  final monthCtrl = FixedExtentScrollController(initialItem: m - 1);
+  final dayCtrl = FixedExtentScrollController(initialItem: d - 1);
+
+  int daysInMonth(int year, int month) =>
+      DateTime(year, month + 1, 0).day;
+
+  void clampDay() {
+    final maxDay = daysInMonth(y, m);
+    if (d > maxDay) d = maxDay;
+  }
+
+  return showCupertinoModalPopup<DateTime>(
+    context: context,
+    builder: (ctx) => Container(
+      height: 320,
+      decoration: const BoxDecoration(
+        color: Colors.white,
+        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
+      ),
+      child: Column(
+        children: [
+          Container(
+            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
+            child: Row(
+              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+              children: [
+                CupertinoButton(
+                  padding: EdgeInsets.zero,
+                  child: const Text('取消', style: TextStyle(fontSize: 16, color: Color(0xFF94A3B8))),
+                  onPressed: () => Navigator.pop(ctx),
+                ),
+                CupertinoButton(
+                  padding: EdgeInsets.zero,
+                  child: const Text('确定', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: AppColors.primary)),
+                  onPressed: () {
+                    clampDay();
+                    Navigator.pop(ctx, DateTime(y, m, d));
+                  },
+                ),
+              ],
+            ),
+          ),
+          Expanded(
+            child: Row(
+              children: [
+                Expanded(child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: yearCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) {
+                    y = minDate.year + i;
+                    clampDay();
+                    final maxDay = daysInMonth(y, m);
+                    dayCtrl.jumpTo((d - 1).clamp(0, maxDay - 1).toDouble());
+                  },
+                  children: [for (var i = minDate.year; i <= maxDate.year; i++) Center(child: Text('$i', style: _pickerItemStyle))],
+                ))),
+                Expanded(child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: monthCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) {
+                    m = i + 1;
+                    clampDay();
+                    final maxDay = daysInMonth(y, m);
+                    dayCtrl.jumpTo((d - 1).clamp(0, maxDay - 1).toDouble());
+                  },
+                  children: [for (var i = 1; i <= 12; i++) Center(child: Text(i.toString().padLeft(2, '0'), style: _pickerItemStyle))],
+                ))),
+                Expanded(child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: dayCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) => d = i + 1,
+                  children: [for (var i = 1; i <= daysInMonth(y, m); i++) Center(child: Text(i.toString().padLeft(2, '0'), style: _pickerItemStyle))],
+                ))),
+              ],
+            ),
+          ),
+        ],
+      ),
+    ),
+  );
+}
+
+Future<TimeOfDay?> showAppTimePicker(
+  BuildContext context, {
+  required TimeOfDay initialTime,
+}) {
+  var hour = initialTime.hour;
+  var minute = initialTime.minute;
+  final hourCtrl = FixedExtentScrollController(initialItem: hour);
+  final minuteCtrl = FixedExtentScrollController(initialItem: minute);
+
+  return showCupertinoModalPopup<TimeOfDay>(
+    context: context,
+    builder: (ctx) => Container(
+      height: 320,
+      decoration: const BoxDecoration(
+        color: Colors.white,
+        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
+      ),
+      child: Column(
+        children: [
+          Container(
+            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
+            child: Row(
+              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+              children: [
+                CupertinoButton(
+                  padding: EdgeInsets.zero,
+                  child: const Text('取消', style: TextStyle(fontSize: 16, color: Color(0xFF94A3B8))),
+                  onPressed: () => Navigator.pop(ctx),
+                ),
+                CupertinoButton(
+                  padding: EdgeInsets.zero,
+                  child: const Text('确定', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: AppColors.primary)),
+                  onPressed: () => Navigator.pop(ctx, TimeOfDay(hour: hour, minute: minute)),
+                ),
+              ],
+            ),
+          ),
+          Expanded(
+            child: Row(
+              children: [
+                const Spacer(flex: 1),
+                Expanded(flex: 2, child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: hourCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) => hour = i,
+                  children: [for (var i = 0; i <= 23; i++) Center(child: Text(i.toString().padLeft(2, '0'), style: _pickerItemStyle))],
+                ))),
+                Expanded(flex: 2, child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: minuteCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) => minute = i,
+                  children: [for (var i = 0; i <= 59; i++) Center(child: Text(i.toString().padLeft(2, '0'), style: _pickerItemStyle))],
+                ))),
+                const Spacer(flex: 1),
+              ],
+            ),
+          ),
+        ],
+      ),
+    ),
+  );
+}
+
+Future<DateTime?> showAppDateTimePicker(
+  BuildContext context, {
+  required DateTime initialDate,
+  DateTime? firstDate,
+  DateTime? lastDate,
+}) {
+  final minDate = firstDate ?? DateTime(1900);
+  final maxDate = lastDate ?? DateTime(2100);
+  var y = initialDate.year.clamp(minDate.year, maxDate.year);
+  var m = initialDate.month;
+  var d = initialDate.day;
+  var h = initialDate.hour;
+  var min = initialDate.minute;
+  final yearCtrl = FixedExtentScrollController(initialItem: y - minDate.year);
+  final monthCtrl = FixedExtentScrollController(initialItem: m - 1);
+  final dayCtrl = FixedExtentScrollController(initialItem: d - 1);
+  final hourCtrl = FixedExtentScrollController(initialItem: h);
+  final minuteCtrl = FixedExtentScrollController(initialItem: min);
+
+  int daysInMonth(int year, int month) =>
+      DateTime(year, month + 1, 0).day;
+
+  void clampDay() {
+    final maxDay = daysInMonth(y, m);
+    if (d > maxDay) d = maxDay;
+  }
+
+  return showCupertinoModalPopup<DateTime>(
+    context: context,
+    builder: (ctx) => Container(
+      height: 320,
+      decoration: const BoxDecoration(
+        color: Colors.white,
+        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
+      ),
+      child: Column(
+        children: [
+          Container(
+            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
+            child: Row(
+              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+              children: [
+                CupertinoButton(
+                  padding: EdgeInsets.zero,
+                  child: const Text('取消', style: TextStyle(fontSize: 16, color: Color(0xFF94A3B8))),
+                  onPressed: () => Navigator.pop(ctx),
+                ),
+                CupertinoButton(
+                  padding: EdgeInsets.zero,
+                  child: const Text('确定', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: AppColors.primary)),
+                  onPressed: () {
+                    clampDay();
+                    Navigator.pop(ctx, DateTime(y, m, d, h, min));
+                  },
+                ),
+              ],
+            ),
+          ),
+          Expanded(
+            child: Row(
+              children: [
+                Expanded(child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: yearCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) { y = minDate.year + i; clampDay(); },
+                  children: [for (var i = minDate.year; i <= maxDate.year; i++) Center(child: Text('$i', style: _pickerItemStyle))],
+                ))),
+                Expanded(child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: monthCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) { m = i + 1; clampDay(); },
+                  children: [for (var i = 1; i <= 12; i++) Center(child: Text(i.toString().padLeft(2, '0'), style: _pickerItemStyle))],
+                ))),
+                Expanded(child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: dayCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) => d = i + 1,
+                  children: [for (var i = 1; i <= daysInMonth(y, m); i++) Center(child: Text(i.toString().padLeft(2, '0'), style: _pickerItemStyle))],
+                ))),
+                Expanded(child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: hourCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) => h = i,
+                  children: [for (var i = 0; i <= 23; i++) Center(child: Text(i.toString().padLeft(2, '0'), style: _pickerItemStyle))],
+                ))),
+                Expanded(child: _wrapPicker(CupertinoPicker(
+                  selectionOverlay: null,
+              scrollController: minuteCtrl,
+                  itemExtent: 40,
+                  onSelectedItemChanged: (i) => min = i,
+                  children: [for (var i = 0; i <= 59; i++) Center(child: Text(i.toString().padLeft(2, '0'), style: _pickerItemStyle))],
+                ))),
+              ],
+            ),
+          ),
+        ],
+      ),
+    ),
+  );
+}
+
+Future<int?> showAppCountPicker(
+  BuildContext context, {
+  required int initialValue,
+  int min = 1,
+  int max = 10,
+  String label = '',
+}) {
+  var selected = initialValue;
+  return showCupertinoModalPopup<int>(
+    context: context,
+    builder: (ctx) => Container(
+      height: 320,
+      decoration: const BoxDecoration(
+        color: Colors.white,
+        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
+      ),
+      child: Column(
+        children: [
+          Container(
+            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 10),
+            child: Row(
+              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+              children: [
+                CupertinoButton(
+                  padding: EdgeInsets.zero,
+                  child: const Text('取消', style: TextStyle(fontSize: 16, color: Color(0xFF94A3B8))),
+                  onPressed: () => Navigator.pop(ctx),
+                ),
+                CupertinoButton(
+                  padding: EdgeInsets.zero,
+                  child: const Text('确定', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: AppColors.primary)),
+                  onPressed: () => Navigator.pop(ctx, selected),
+                ),
+              ],
+            ),
+          ),
+          Expanded(
+            child: _wrapPicker(CupertinoPicker(
+              selectionOverlay: null,
+              scrollController: FixedExtentScrollController(initialItem: selected - min),
+              itemExtent: 40,
+              onSelectedItemChanged: (i) => selected = i + min,
+              children: [
+                for (var i = min; i <= max; i++)
+                  Center(child: Text(label.isEmpty ? '$i' : '$i$label', style: _pickerItemStyle)),
+              ],
+            )),
+          ),
+        ],
+      ),
+    ),
+  );
+}
+
 class AppBackground extends StatelessWidget {
   final Widget child;
   final bool safeArea;